JP2003032115A - Integral type analog to digital converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integral type analog/digital converter that can integrate an input signal for a time required for analog/digital conversion and correct an error due to the effect of offset, dispersion and temperature change or the like on the basis of the measurement result so as to measure an integral value of consecutively received signals with high accuracy. SOLUTION: The integral type analog/digital converter is provided with two systems of integral type analog/digital conversion sections 100, 200, alternately selects them for each prescribed period, allows one of the integral type analog/digital conversion sections to integrate the input signal and the other to apply analog/digital conversion to the integrated input signal. Further, the integral type-analog/digital converter utilizes a margin time after analog/digital converting the input signal to conduct ground voltage integration, apply analog/ digital conversion to the integrated ground voltage, reference voltage integration and apply analog/digital conversion to the integrated reference voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integral A / D converter for measuring a direct current, and more particularly to an integral A / D converter suitable for measuring an integrated value of a charge / discharge current of a battery.

[0002]

2. Description of the Related Art Notebook computers, personal mobile terminals (PD
A rechargeable battery is often used as a power source for various electric devices such as A), a digital still camera (DSC), a smart phone, an electric vehicle, and an electrically assisted bicycle.

In these batteries, for example, batteries such as lithium-ion batteries used in notebook computers, there is a risk of bursting if overcharged by exceeding the rating during charging, and conversely, the capacity is reduced. If the discharge is exceeded, the charging / discharging characteristics will deteriorate.

In order to avoid such a situation and to bring out the full performance of the battery, it is necessary to perform charging and discharging control suitable for the charging and discharging characteristics. Therefore, a measuring device for monitoring the charge / discharge state of the battery has been conventionally used.

The conventional measuring device uses a charging / discharging current (for example, 0.5 mA to 15 A) that varies over a wide range as a voltage (5 μV).
To 150 mV), the converted voltage is amplified, sample-held, converted into a digital signal by a multi-bit (for example, 10-bit) successive approximation A / D converter, and averaged. It is composed of a microcontroller unit (MCU) and the like.

In this conventional measuring apparatus, since the integrated value of the charging / discharging current is obtained based on the product of the discrete value obtained at each predetermined sampling cycle and the time, there is an error in the integrated value, and the dynamic value of the input signal. Since the range is wide and it is affected by continuous minute current and noise, it has been difficult to improve the accuracy of current integrated value measurement. Further, since the operating time of the MCU that consumes a relatively large current is long, it is difficult to reduce the power consumption.

FIG. 10 shows the configuration of a conventionally known integral type A / D converter that performs continuous value integration and A / D conversion, and FIG. 8 shows a timing chart thereof.
In FIGS. 10 and 11, first, the integrating circuit 101 is reset, and the integrated output Ea has a zero voltage. In this state, when the start pulse s is applied and the flip-flop 103 is set, the switch S1 is turned on, the switch S2 is turned off, and the input signal Ei is connected. The integrating circuit 101 starts the integration of the input signal Ei, and the first integration period Ts, which is the reference period, starts and the slope −E.
The output Ea of i / RC is generated, and the output Ea is the comparison voltage −ΔV.
If t is exceeded, the comparison pulse p is generated.

As a result, the AND circuit 106 is opened and the counter 104 starts counting the clock pulses of the clock pulse generation circuit 105. After a certain time Ts, the count value of the counter 104 reaches the overflow value Nm,
Flip-flop 103 by overflow pulse r
Is reset.

Therefore, this time, the switch S1 is turned off,
The switch S2 is turned on, the reference voltage is switched to the −Es side, the second integration period T is started, and the integration circuit 101 performs the integration of the slope Es / CR opposite to the previous one. And output Ea
Is returned to the comparison voltage −ΔVt, the comparison circuit 102 is inverted,
The AND circuit 106 is closed. During this time, the counter 104
Is counting from 1 again after overflow,
The count value N when the AND circuit 106 is closed is a value proportional to the input signal Ei.

In this way, the input signal E in the integrating circuit 101 is
i is integrated only for the reference period Ts, then the integrating circuit 101 is switched to the reference voltage −Es having a polarity opposite to that of the input signal Ei, and the integrated value is integrated back to zero. Since the integrated value of the first half of the integrating circuit 101 is proportional to the value of the input signal Ei, the backward integration time T of the latter half is proportional to the value of the input signal Ei, and the clock pulse is counted during this period to perform A / D conversion. It was done. This conventional integration type A / D converter has an advantage that the circuit can be constructed at a low cost and is hardly affected by noise.

[0011]

However, in the conventional A / D converter, in addition to the integration period for integrating the input signal, the reverse integration time for discharging the integrated value at the reference voltage, that is, A This requires A / D conversion time.
The input signal cannot be integrated during the conversion time.

Therefore, when measuring the integrated value of the input signal such as a continuous current, there occurs a period in which the integrated signal is not integrated and A / D converted. Even if the input signal in this period is predicted and corrected by an averaging means or the like, it is difficult to obtain a highly accurate measurement result. In particular, in the case of measuring the integrated value of the charging / discharging current of the battery in which the range of change of the input signal is wide, the influence of this error is large.

Further, there is an offset component in the amplifier and the comparator in the analog system of this conventional A / D converter, and further, due to the characteristic variation and temperature change of these constituent elements, the measured data value is changed. There will be fluctuations.

It is difficult to improve the accuracy because of the error amount due to the effects of offset, variation, temperature change and the like.

In view of the problems of these conventional devices, the present invention has a configuration capable of integrating an input signal during the time required for A / D conversion, and measures an error amount due to an influence of offset, variation, temperature change, and the like. It is an object of the present invention to provide an integration type A / D converter that can be corrected based on the result and can measure the integrated value of continuously input signals with high accuracy.

[0016]

An integral type A / D according to claim 1
The converter receives a first integration type A / D conversion section, a second integration type A / D conversion section, an input signal, and outputs the input signal every predetermined period to the first integration type A / D conversion section. And input means for alternately supplying to the second integration type A / D conversion section, and A / of the input signal converted by the first integration type A / D conversion section.
The D conversion data and the A / D conversion data of the input signal converted by the second integration type A / D conversion unit are respectively converted into the first integration type A / D conversion unit and the second integration type A. / D
Output means for receiving from the conversion part and outputting to the outside, the first integration type A / D conversion part and the second integration type A / D
Each of the D conversion units is characterized by integrating an input signal input during a certain predetermined period and performing A / D conversion of an integrated value of the input signal during a subsequent predetermined period.

The integral type A / D converter according to the present invention is provided with two systems of integral type A / D converters, which are alternately switched at predetermined intervals, and one of the integral type A / D converters inputs the input signal. Is performed and the input signal integrated by the other integral type A / D conversion unit is A / D converted, so that the integrated value of the continuously changing input signal can be accurately calculated based on actual measurement. It can be measured.

An integral type A / D converter according to a second aspect of the invention has a first integral type A / D conversion section, a second integral type A / D conversion section, an input signal, and a reference voltage. , The input signal is alternately supplied to the first integration type A / D conversion section and the second integration type A / D conversion section every predetermined period, and the input signal is not supplied to the second integration type A / D conversion section. Input means for supplying the reference voltage to the integration type A / D conversion section or the first integration type A / D conversion section, and A / A of the input signal converted by the first integration type A / D conversion section. D
The conversion data, the A / D conversion data of the reference voltage, the A / D conversion data of the input signal converted by the second integral type A / D conversion unit, and the A / D conversion data of the reference voltage are respectively converted into the second data. 1 integral type A / D conversion section and output means for receiving from the second integral type A / D conversion section and outputting to the outside, the first integral type A / D conversion section and the second Each of the integral A / D converters integrates an input signal input during a certain predetermined period, A / D converts the integrated value of the input signal during a subsequent predetermined period, and
It is characterized in that reference voltage integration and reference A / D conversion are performed.

According to the integral type A / D converter of the second aspect of the invention, similarly to the integral type A / D converter of the first aspect of the invention, the integrated value of the continuously changing input signal is accurately measured and accurately calculated. Can be measured.

Further, in the A / D conversion period of the integrated input signal, the margin period after the A / D conversion of the input signal is utilized to integrate the reference voltage and the reference A / D thereof.
By performing the D conversion, the reference data is obtained together with the data of the input signal. Since the reference signal can be used to correct the input signal data such as ratio processing, the measurement accuracy can be further improved.

The reference voltage integration and the reference A / D conversion are performed by integrating the input signal or the A / D thereof.
Since the conversion is performed by utilizing the free time of the integration type A / D conversion unit, the conversion unit can be efficiently used.

An integral A / D converter according to a third aspect is the integral A / D converter according to the second aspect, wherein the reference voltage is a ground voltage, and ground voltage integration and ground A / D conversion are performed. The offset voltage is obtained by

According to the integral type A / D converter of the third aspect of the present invention, similarly to the integral type A / D converter of the first aspect, the integrated value of the continuously changing input signal can be accurately determined based on the actual measurement. Can be measured.

In the A / D conversion period of the integrated input signal, the ground voltage integration and the ground A / D conversion are performed by using the margin period after the A / D conversion of the input signal. Offset data is obtained together with the data of the input signal. Since the offset data can be used to correct the input signal data such as difference processing, the measurement accuracy can be further improved.

Further, since the ground voltage integration and the ground A / D conversion are carried out by utilizing the free time of the integral type A / D conversion section which does not carry out the integration of the input signal or the A / D conversion thereof. The parts can be used efficiently.

An integral A / D converter according to a fourth aspect of the present invention receives a first integral A / D converter, a second integral A / D converter, an input signal, and a first reference voltage. A second reference voltage is provided, and an input signal is supplied to the first integration type A / D conversion unit and the second integration type A at predetermined intervals.
To the second integration type A / D conversion section or the first integration type A / D conversion section to which an input signal is not supplied. Input means for supplying a voltage or a second reference voltage, A / D conversion data of the input signal converted by the first integral A / D conversion section, A / D conversion data of the first reference voltage, second A / D conversion data of the reference voltage, A / D conversion data of the input signal converted by the second integration type A / D conversion unit, A / D conversion data of the first reference voltage, and second reference voltage A / D
Output means for receiving the converted data from the first integration type A / D conversion section and the second integration type A / D conversion section and outputting the converted data to the outside, respectively. The conversion unit and the second integration type A / D conversion unit each integrate an input signal input during a predetermined period, and A / D-convert the integrated value of the input signal during a subsequent predetermined period. First reference voltage integration and first reference A /
It is characterized by performing D conversion or second reference voltage integration and second reference A / D conversion.

According to the integral type A / D converter of the present invention, as in the integral type A / D converter of the first aspect, the integrated value of the continuously changing input signal is accurately measured and accurately calculated. Can be measured.

In the cycle of A / D converting the integrated input signal, the first reference voltage integration and the first reference A / D conversion are performed by using the margin period after the A / D conversion of the input signal. , The second reference voltage integration and the second reference A / D conversion are performed to obtain the first reference data and the second reference data together with the data of the input signal. By using the first reference data and the second reference data, the input signal data can be corrected by the difference processing, the ratio processing, and the like, so that the measurement accuracy can be further improved.

The first reference voltage integration and the first reference A / D conversion, and the second reference voltage integration and the second reference A / D conversion perform integration of the input signal or A / D conversion thereof. Not integrated type A /
Since the free time of the D conversion unit is used, the conversion unit can be efficiently used.

According to a fifth aspect of the present invention, there is provided an integral A / D converter according to the first to fourth aspects, wherein the output means converts the A / D conversion data into positive / negative signs indicating the contents of the data and conversion. It is characterized in that additional information including a part identification code and a data type code is added and output in a predetermined data format.

In the integral type A / D converter according to the present invention, the A / D conversion data and the additional information (positive / negative code, converter identification code, data type code) are output based on a predetermined data format. Data transmission and reception processing can be facilitated and troubles can be prevented.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a configuration of an integral type A / D converter according to a first embodiment of the present invention, and FIG. 2 is a whole integral type A / D converter according to the first embodiment. Is a timing chart as. In addition, FIG.
FIG. 4 is a diagram showing an internal configuration of an A / D conversion unit, and FIG.
It is a timing chart of a conversion part.

In FIGS. 1 and 2, the direct current I flows through the current detection resistor R, and the voltage drop across the resistor R is the input voltage Vi.
n. This DC current I has positive and negative polarities in the case of battery charging / discharging current, and its magnitude fluctuates in a wide range (for example, 0.5 mA to 15 A), and the input voltage Vin also varies accordingly. Fluctuate.

This input voltage Vin is switched to T (T1, T2 ...) At predetermined intervals by the input changeover switch SW9 and the input changeover switch SW10, and the 0 channel A / D conversion section 100 or the 1 channel A / D conversion is performed. Part 2
00 are alternately input.

The 0-channel A / D conversion unit 100 and the 1-channel A / D conversion unit 200 are respectively integrated type A / D converters.
The conversion unit receives various timing signals TC and clock signals and integrates the signals input to the input terminals in-0 and in-1 for a predetermined period T1 (or A / D).
Converted), and the integrated value is A / D converted (or integrated) in the subsequent predetermined period T2, and the A / D converted values k0 and k1 are output from the output terminals out0 and out1. Further, both conversion units 100 and 200 supply a positive / negative code, a conversion unit identification code, a data type code, etc., representing the data content of each A / D conversion value to the register 40.

The register 40 has an output changeover switch SW8.
A / D conversion values k0 and k1 on the side to which is connected are input, and a plus / minus code representing the data content of the A / D conversion values k0 and k1, a conversion unit identification code, a data type code, and the like are added information, Data is output with the A / D converted values k0 and k1. A timing signal is applied to the output change-over switch SW8 so as to be connected to one of the output terminals out0 and out1 each time the A / D conversion corresponding to one integrated value is completed.

The clock pulse generator 50 converts the clock signal, which is the time reference of the present apparatus, into each A / D converter 100,
It is supplied to the counter in 200 and the timing controller 60. The timing controller 60 receives a clock signal and an external operation signal as necessary, creates various timing signals TC (TC1 to TCn), and supplies them to respective required locations. Further, the 0-channel A / D conversion unit 100 and the 1-channel A / D conversion unit 200 are linked to each other, and various types of signals are provided according to the states of the 0-channel A / D conversion unit 100 and the 1-channel A / D conversion unit 200. Form and supply timing signal TC.

FIG. 3 shows a 0-channel A / D converter 10
FIG. 3 is a diagram showing an internal configuration of a 0, 1 channel A / D conversion unit 200. In the figure, the voltage applied to the input terminal in is supplied to the integrator 10 via the switch SW1 which is closed in the ON state by the timing signal TC1 during the integration period, and passes through the high resistance input resistor Ri. It is supplied to the inverting input terminal of the amplifier Ai.

The inverting input terminal of the amplifier Ai of the integrator 10 is supplied with the constant current Id from the power supply voltage Vcc by the constant current source I2 through the switch SW3. The switch SW3 is turned on during the A / D conversion operation when the output voltage of the integrator 10 has a positive polarity. The inverting input terminal of the amplifier Ai is connected to the ground voltage Vgnd to the constant current source I
1, the constant current Iu is supplied via the switch SW2. The switch SW2 is turned on during the A / D conversion operation when the output voltage of the integrator 10 has a negative polarity.

The constant current Iu and the constant current Id are usually the same current value, but their magnitudes are determined by the magnitude of the input current by the input signal Vin and the output dynamic range of the integrator. That is, the output of the integrator, which is generated by the difference between the input current of the input signal Vin and the charge accumulated in the capacitor Ci during the integration period T0, is determined to be within the dynamic range. It That is, {(Vin / Ri) -Iu} × T0 / Ci ≦ integrator 1
Output dynamic range of 0

The integrator 10 is composed of an amplifier Ai, a resistor Ri and a capacitor Ci, the resistor Ri is connected to the inverting input terminal of the amplifier Ai, and the capacitor Ci is provided between the inverting input terminal and the output terminal of the amplifier Ai. It is connected and functions as an integrating amplifier. The non-inverting input terminal of the amplifier Ai is connected to the ground voltage Vgnd or a predetermined bias potential. A switch SW4 is connected between the terminals of the capacitor Ci, and this switch SW4 is momentarily closed in order to erase the residual charge when a new integration period starts.

The comparator Cz has an integrator 1 at its non-inverting input terminal.
The output voltage c of 0 is the ground voltage Vgn at the inverting input terminal.
d or a predetermined bias potential Vb is supplied, and the comparison output d is inverted and output depending on whether the output voltage c is positive or negative or higher or lower than a predetermined value Vb. In addition to the comparator Cz, a positive potential detection comparator and a negative potential detection comparator are provided to detect a predetermined positive / negative voltage of the output voltage c of the integrator 10, and the output voltage is determined depending on the detection conditions. You may make it determine c.

The control logic means 20 receives the comparison output d and the timing signal and outputs the up-count signal LO1 and the down-count signal LO2. This up-count signal LO1 is the output voltage c of the integrator 10.
Is a negative polarity and is turned on from a time point before a predetermined time Tb before the end of the integration period of the input signal until the comparison output d is inverted. Also, the down count signal L
The output voltage c of the integrator 10 has a positive polarity, and O2 is turned on from a time point that is a predetermined time Tb before the time point when the integration period of the input signal ends, until the comparison output d is inverted. The predetermined time Tb can be appropriately determined according to the magnitude of the input signal Vin, the magnitude of the low currents Iu and Id, and the time Tb can be zero.

The up / down counter 30 has an up count terminal U, a down count terminal D, a count output terminal O and a reset terminal R. A timing signal TC2 for resetting the count value when a new integration period starts is applied to the reset terminal R.

The clock signal CLK is input to the up-count terminal U while the switch SW5 is closed by the up-count signal LO1 to count up. A down count signal L is applied to the down count terminal D.
While the switch SW6 is closed by O2, the clock signal CLK is input and down counting is performed.

FIG. 4 shows the 0 channel A / shown in FIG.
6 is a simple timing chart showing the operation of the D conversion unit 100. Note that the operation of the 1-channel A / D conversion unit 200 has a similar timing chart, but the integration period and the A / D conversion period have a positional relationship opposite to that in FIG.

In FIG. 4, the timing signal TC1
Is output during the integration period T1 and is supplied to the switch SW1 and the control logic means 20. The timing signal TC2 is output at the time when a new integration period starts, and is supplied to the switch SW4 and the counter 30. The timing signal TC3 is an A / D conversion operation timing signal and is supplied to the control logic means 20. Other timing signals are formed and used as needed.

In the integration period T1, the input positive signal a is integrated by the integrator 10, and the integrated output c gradually increases. Upon receiving this integrated output c, the comparison output d of the comparator Cz is at a low level (negative state).

In this state, when the A / D conversion operation starts, that is, the time Tb before the end of the integration period T1 is reached, the A / D conversion operation precedes the A / D conversion period T2. Be started. Since the comparison output d has a negative polarity, the control logic means 20 generates the up-count signal LO1.

The up-count signal LO1 is first supplied to the switch SW5 to close it. While the switch SW5 is closed, the clock signal from the clock pulse generator 50 is supplied to the up-count terminal U of the counter 30, and the count value of the counter 30 is up-counted. At the same time, the up-count signal LO1 changes to the switch S.
It is supplied to W2 and closed. The constant current Iu flows out from the capacitor Ci of the integrator 10 while the switch SW2 is closed.

In the period Tb from the generation of the up-count signal LO1 to the end of the integration period T1,
The input current Vin / Ri is charged and the low current Iu is discharged at the same time. When the integration period T1 ends, the input selector switch SW9 is switched from the input signal terminal a side to the ground terminal g side, and the switch SW1 is turned off.

Subsequently, by discharging the constant current Iu, c
When the point potential gradually recovers and reaches the zero potential of the comparator Cz, the comparison output d is inverted and applied to the control logic means 20. Control logic means 20
Then, the up count signal LO1 is stopped by the inversion of the second comparison output d. As a result, the switch SW5 is opened, the up-counting operation of the counter 30 is stopped, the switch SW2 is opened, and the outflow of the constant current Iu is stopped.

In this way, the up-count pulse i corresponding to the integrated value of the input signal a is counted and output from the counter 30 as the count value k. By performing the A / D conversion operation during the integration period T1 as described above, the time required for A / D conversion of the integrated value can be shortened. Further, although the case where the input signal a has a positive polarity has been described above as an example, the same processing is performed when the signal a has a negative polarity, and a digital value by down-counting is obtained.

The overall operation of the integral type A / D converter of the first embodiment configured as described above will be described with reference to the timing chart of FIG. 2 again.

The input changeover switch SW9 and the input changeover switch SW10 are changed over every predetermined period T by the timing signal TC from the timing controller 60, and the input signal Vin is alternately applied to the 0 channel A / D converter 100 or 1 channel. It is supplied to the A / D conversion unit 200.

The input signal Vin is 0 in the first period T1.
It is supplied to the channel A / D conversion unit 100 and integrated. On the other hand, the 1-channel A / D conversion unit 200 performs A / D conversion on the integrated value of the input signal integrated in the previous period. In FIG. 2, the period of is the integration period of the input signal,
The period of indicates the A / D conversion period of the integrated value of the input signal. The A / D conversion operation may be performed during the integration period of the input signal as described above. This point is the same in the other embodiments.

In the subsequent second period T2, the input changeover switch SW9 and the input changeover switch SW10 are changed over in reverse, and the input signal Vin is supplied to the 1-channel A / D conversion section 200 and integrated, while the 0-channel A / D is changed.
The conversion unit 100 performs A / D conversion on the integrated value of the input signal that has been integrated in the previous period.

In this way, the 0-channel A / D converter 1
The 00 and 1-channel A / D converters 200 alternately perform the integration of the input signal and the A / D conversion of the integrated value every predetermined period, and output the A / D converted values k0 and k1 from the output terminals out0 and out1. Output. Then, the A / D conversion value k0 on the side to which the output changeover switch SW8 is connected,
k1 is input to the register 40, and its A / D conversion value k
Data is output with additional information indicating the data contents of 0 and k1.

Integral type A / D according to the first embodiment
In the converter, two channels of 0-channel A / D converter 1
00, 1-channel A / D conversion unit 200 is alternately switched every predetermined period, one integration type A / D conversion unit performs integration of the input signal, and the other integration type A / D conversion unit performs integration. Since the continuously changing input signal is integrated seamlessly by A / D converting the input signal thus obtained, the integrated value can be measured with high accuracy and based on actual measurement.

FIG. 5 is a diagram showing the configuration of an integral type A / D converter according to the second embodiment of the present invention.
3 is a timing chart of the integral type A / D converter as a whole.

In FIG. 5, as in FIG. 1, the direct current I
Flows into the current detection resistor R, and the voltage drop across the current detection resistor R becomes the input voltage Vin. The input voltage Vin is switched by the input changeover switch SW9a and the input changeover switch SW10a in every predetermined cycle, and is alternately input to the 0-channel A / D converter 100 or the 1-channel A / D converter 200. The input changeover switch SW9a and the input changeover switch SW10a are each of a three-input changeover type, and in addition to the input voltage Vin by the timing signal TC,
It is switchably connected to the ground voltage Vgnd and the reference voltage Vref.

The 0-channel A / D conversion unit 100 and the 1-channel A / D conversion unit 200 are respectively integrated type A / D converters.
The conversion unit receives various timing signals TC and clock signals, integrates the signals input to the input terminals in-0 and in-1, and A / D-converts the integrated value after the integration is completed.
The A / D converted values k0 and k1 are output to output terminals out0 and ou.
Output from t1.

The register 40 has an output changeover switch SW8.
The A / D conversion values k0 and k1 on the side to which is connected are input, and additional information representing the data content of the A / D conversion values k0 and k1 such as a positive / negative code, a conversion unit identification code, and a data type code is input. Attach and output the data. A timing signal is applied to the output change-over switch SW8 so as to be connected to one of the output terminals out0 and out1 each time the A / D conversion corresponding to one integrated value is completed.

The clock pulse generator 50 supplies a clock signal, which serves as a time reference of this apparatus, to the counter 30 and the timing controller 60. The timing controller 60 receives a clock signal and an external operation signal as necessary, creates various timing signals TC, and supplies them to required portions. Also, 0 channel A / D
In cooperation with the conversion unit 100 and the 1-channel A / D conversion unit 200, various timing signals TC are formed and supplied according to the states of the 0-channel A / D conversion unit 100 and the 1-channel A / D conversion unit 200. To do.

The 0-channel A / D converter 100,
The internal configuration and operation of the 1-channel A / D conversion unit 200 are the same as those in FIGS. 3 and 4, but the ground voltage Vgnd and the reference voltage Vr are maintained even during the A / D conversion period.
During the period in which ef is integrated, the timing signal TC1 is output and the switch SW1 is turned on. In addition, during the period in which the integrated value voltage of the ground voltage Vgnd and the integrated value voltage of the reference voltage Vref are A / D converted, the timing signal TC3 is output and the up count signal LO1 (or the down count signal LO2) is output, The up / down counter 30 counts according to the integrated value voltage. The other operations are the same, so the description thereof will be omitted.

The overall operation of the integral type A / D converter of the second embodiment configured as described above will be described with reference to the timing chart of FIG. In FIG. 6, the period is the integration period of the input signal, the period is the A / D conversion period of the integration value of the input signal, the period is the integration period of the ground voltage, and the period is the A / D conversion of the ground integration value. The period of, and the period of are the integration period of the reference voltage, and the period of is the A / D conversion period of the reference voltage integrated value.

The input changeover switch SW9a and the input changeover switch SW10a are switched and connected to the input voltage Vin, the ground voltage Vgnd and the reference voltage Vref by the timing signal TC from the timing controller 60.

The input selector switch SW9a is connected to the input voltage Vin during the first period T1, is connected to the ground voltage Vgnd during the second period, is connected to the input voltage Vin during the third period T3, and is connected to the fourth period. Then, it is switched and connected to the reference voltage Vref. Also, the input selector switch S
W10 has the reference voltage Vref in the first period T1.
Connected to the input voltage Vin during the second period T2, connected to the ground voltage Vgnd during the third period T3, and switched to the input voltage Vin during the fourth period T4.

In the first period T1, 0 channel A /
The D conversion unit 100 integrates the input signal Vin, while
The channel A / D conversion unit 200 first A / D-converts the integrated value of the input signal that has been integrated in the previous period, then integrates the reference voltage, and further A / D-converts this reference integration. .

In the second period T2, 0 channel A /
The D conversion unit 100 first A / D-converts the integrated value of the input signal integrated in the preceding first period T1, then integrates the ground voltage, and further A / D-converts the integrated value of the ground voltage. To do. A / of the integrated value of this ground voltage
An offset voltage is obtained by D conversion. Further, the 1-channel A / D conversion unit 200 integrates the input signal Vin.

In the third period T3, 0 channel A /
The D conversion unit 100 integrates the input signal Vin, while
The channel A / D conversion unit 200 first A / D-converts the integrated value of the input signal that has been integrated in the preceding second period T2, then performs the integration of the ground voltage, and further the A of the integrated value of the ground voltage. / D conversion is performed.

In the fourth period T4, 0 channel A /
The D conversion unit 100 first A / D-converts the integrated value of the input signal integrated in the previous third period T3, then performs integration of the reference voltage, and further A / D-converts the integrated value of the reference voltage. To do. Also, 1 channel A /
The D conversion unit 200 integrates the input signal Vin.

In this way, the 0-channel A / D converter 1
In the 00 and 1-channel A / D converters 200, the integration of the input signal, the A / D conversion of the integrated value of the input signal, the integration of the ground voltage, the A / D conversion of the integrated value of the ground voltage, or A of the integrated value of the input signal
The D / D conversion, the integration of the reference voltage, and the A / D conversion of the integrated value of the reference voltage are alternately performed. A / D conversion of the integrated value of the input signal, A / D of the integrated value of the ground voltage
The respective values of the D conversion and the A / D conversion of the reference voltage integrated value are sequentially output from the output terminals out0 and out1 as A / D converted values k0 and k1.

Then, the A / D conversion values k0 and k1 on the side to which the output changeover switch SW8 is connected are input to the register 40, and additional information indicating the data contents of the A / D conversion values k0 and k1 is added. And output the data.

This additional information is provided in order to avoid confusion on the transmitting and receiving sides, because the data cannot be distinguished when the outputs of the two systems of A / D converters are taken out from one system. Yes, it is formed in the data format illustrated in FIG.

In FIG. 7, bit number 1 is a plus / minus sign, bit numbers 2 to 17 are count data which are A / D conversion data, bit number 18 is a system number for identifying the conversion section, and bit numbers 17 and 18 are input voltages. , Ground, reference data type code, and bit numbers 21 and 22 are reserved.

By outputting the A / D converted data and the additional information (a positive / negative code, a conversion section identification code, a data type code) based on this predetermined data format, data transmission and reception processing can be facilitated and troubles can be prevented. Occurrence can be prevented.

Integral type A / D according to the second embodiment
In the converter, similarly to the integration type A / D converter in FIG. 1, the integrated value of the continuously changing input signal can be measured with high accuracy and based on actual measurement.

Further, in the cycle of A / D converting the integrated input signal, the ground voltage integration and the A / D conversion of the ground voltage integrated value are performed by utilizing the margin period after the A / D conversion of the input signal. By performing reference voltage integration and A / D conversion of the integrated value of the reference voltage, offset data and reference data are obtained together with the data of the input signal.

Although it is unavoidable that offset error components that exist in analog components such as amplifiers and comparators are included in the integrated value of the input signal, by integrating the ground voltage separately from the input signal, Get the offset voltage,
By performing arithmetic processing such as taking a difference from the measured value of the input signal, the error can be reduced and highly accurate measurement can be performed.

Similarly, an error is included in the integrated value of the input signal due to variations in characteristics of analog components such as amplifiers and comparators and variations in ambient temperature. A known reference voltage integrated value is obtained by integrating the reference voltage separately from the input signal, the data variation ratio of the reference voltage integrated value is calculated, and the calculated data variation ratio is multiplied by the input signal integrated value. It is possible to perform correction by performing arithmetic processing such as to reduce the error and perform highly accurate measurement.

FIG. 8 shows an integral type A according to the third embodiment.
It is a timing chart of a / D converter. The configuration of the integral type A / D converter according to this embodiment corresponds to the configuration in which the reference voltage integration and its reference A / D conversion are eliminated in the second embodiment. Therefore, the configuration diagram of the present embodiment shows that the reference voltage Vr
It is the same as the configuration diagram of FIG. 5 according to the second embodiment except that there is no ef and that the input changeover switch SW9a and the input changeover switch SW10a do not have the changeover to the reference voltage Vref.

Therefore, the operation of the integral type A / D converter of the third embodiment will be described below with reference to the timing chart of FIG. Is omitted for simplicity. In FIG. 8, the period of is the integration period of the input signal, the period of is the A / D conversion period of the integration value of the input signal, the period of is the integration period of the ground voltage, and the period of is the A / D of the ground integration value.
It is a D conversion period.

Now, the input changeover switch SW9a is the first
It is connected to the input voltage Vin during the period T1, is connected to the ground voltage Vgnd during the second period, is connected to the input voltage Vin during the third period T3, and is connected to the ground voltage V during the fourth period.
It is switched and connected to gnd. Also, the input selector switch SW
10a is connected to the ground voltage Vgnd in the first period T1, and is connected to the input voltage Vin in the second period T2.
It is connected to the ground voltage Vgnd in the third period T3, and is switched and connected to the input voltage Vin in the fourth period T4.

In the first period T1, 0 channel A /
The D conversion unit 100 integrates the input signal Vin, while
The channel A / D converter 200 first A / D-converts the integrated value of the input signal that has been integrated in the preceding period, then integrates the ground voltage, and further A / D-converts the ground voltage integrated value. I do.

In the second period T2, 0 channel A /
The D conversion unit 100 first A / D-converts the integrated value of the input signal integrated in the preceding first period T1, then integrates the ground voltage, and further A / D-converts the integrated value of the ground voltage. To do. 1-channel A / D converter 200
Integrates the input signal Vin.

After that, the above-described repetitive operation is performed in the third period T3 and the fourth period T4.

In this way, the 0-channel A / D converter 1
The 00 and 1-channel A / D converters 200 perform integration of the input signal, A / D conversion of the integrated value of the input signal, integration of the ground voltage, and A / D conversion of the integrated value of the ground voltage for each predetermined period. Alternate. A / D conversion of the integrated value of the input signal, A / D of the integrated value of the ground voltage
The respective converted values are sequentially output from the output terminals out0 and out1 as A / D converted values k0 and k1.

Then, the A / D conversion values k0 and k1 on the side to which the output selector switch SW8 is connected are input to the register 40, and additional information indicating the data content of the A / D conversion values k0 and k1 is added. And output the data. This additional information is similar to the data format illustrated in FIG.

Integral type A / D according to the third embodiment
In the converter, similarly to the integration type A / D converter in FIG. 1, the integrated value of the continuously changing input signal can be measured with high accuracy and based on actual measurement.

Further, in the A / D conversion cycle of the integrated input signal, the margin period after the A / D conversion of the input signal is utilized to integrate the ground voltage and the A / D conversion of the integrated value of the ground voltage. By doing so, the offset data is obtained together with the data of the input signal.

Although it is unavoidable that the offset error amount that exists in analog system components such as an amplifier and a comparator is included in the integrated value of the input signal, the offset can be obtained by integrating the ground voltage separately from the input signal. By obtaining the voltage and performing arithmetic processing such as taking the difference from the measured value of the input signal, it is possible to reduce errors and perform highly accurate measurement.

FIG. 9 shows an integral type A according to the fourth embodiment.
It is a timing chart of a / D converter. The configuration of the integral type A / D converter according to this embodiment corresponds to the configuration in which the integration of the ground voltage and the A / D conversion of the integrated value of the ground voltage are eliminated in the second embodiment.
Therefore, the configuration diagram of the present embodiment shows that the ground voltage V
5 is the same as the configuration diagram of FIG. 5 according to the second embodiment, except that there is no gnd and the input changeover switch SW9a and the input changeover switch SW10a do not have a changeover to the ground voltage Vgnd.

Therefore, the overall operation of the integral type A / D converter of the fourth embodiment will be described below with reference to the timing chart of FIG. 9, but it overlaps with that of the second embodiment. The points are omitted for simplification.
In FIG. 9, the period is the integration period of the input signal, the period is the A / D conversion period of the integrated value of the input signal, the period is the integration period of the reference voltage, and the period is the A / D conversion of the reference integrated value. It is a period.

Now, the input changeover switch SW9a is the first
It is connected to the input voltage Vin during the period T1, is connected to the reference voltage Vref during the second period, is connected to the input voltage Vin during the third period T3, and is switch-connected to the reference voltage Vref during the fourth period. The input changeover switch SW10a is connected to the reference voltage Vref in the first period T1 and the input voltage Vin in the second period T2.
Connected to the reference voltage Vre during the third period T3.
It is connected to f and is switched and connected to the input voltage Vin during the fourth period T4.

In the first period T1, 0 channel A /
The D conversion unit 100 integrates the input signal Vin, while
The channel A / D conversion unit 200 first A / D-converts the integrated value of the input signal that has been integrated in the previous period, then performs integration of the reference voltage, and further A / D-converts this reference voltage integrated value. I do.

In the second period T2, 0 channel A /
The D conversion unit 100 first A / D-converts the integrated value of the input signal integrated in the preceding first period T1, then integrates the reference voltage, and further A / D-converts the integrated value of the reference voltage. To do. The 1-channel A / D converter 200 integrates the input signal Vin.

After that, the above-described repetitive operation is performed in the third period T3 and the fourth period T4.

In this way, the 0-channel A / D converter 1
The 00 and 1-channel A / D converters 200 perform integration of the input signal, A / D conversion of the integrated value of the input signal, integration of the reference voltage, and A / D conversion of the integrated value of the reference voltage at predetermined intervals. Alternate. The respective values of A / D conversion of the integrated value of the input signal and A / D conversion of the reference voltage integrated value are converted into A / D converted values k.
0 and k1 are sequentially output from the output terminals out0 and out1.

Then, the A / D conversion values k0 and k1 on the side to which the output changeover switch SW8 is connected are input to the register 40, and additional information indicating the data contents of the A / D conversion values k0 and k1 is added. And output the data. This additional information is similar to the data format illustrated in FIG.

Integral type A / D according to the fourth embodiment
In the converter, similarly to the integration type A / D converter in FIG. 1, the integrated value of the continuously changing input signal can be measured with high accuracy and based on actual measurement.

Further, in the cycle of A / D converting the integrated input signal, the reference voltage integration and the reference A of the reference voltage are utilized by utilizing the margin period after the A / D conversion of the input signal.
By performing the / D conversion, the reference data is obtained together with the data of the input signal.

Due to variations in the characteristics of analog components such as amplifiers and comparators and variations in the ambient temperature, the integrated value of the input signal will include an error. A known reference voltage integrated value is obtained by integrating the reference voltage separately from the input signal, the data variation ratio of the reference voltage integrated value is calculated, and the calculated data variation ratio is multiplied by the input signal integrated value. Compensate by performing arithmetic processing such as
Highly accurate measurement is possible with less error.

[0105]

According to the integral type A / D converter of the first aspect, the integral type A / D converter is provided with two systems of integral type A / D converters, which are alternately switched every predetermined period. Integrates the input signal and A / D-converts the input signal integrated by the other integral-type A / D converter to accurately measure the integrated value of the continuously changing input signal. Based on this, it is possible to measure accurately.

According to the integral type A / D converter of claim 2,
Similar to the integral type A / D converter of claim 1, the integrated value of the continuously changing input signal can be measured with high accuracy and based on actual measurement.

In the cycle of A / D converting the integrated input signal, the reference voltage integration and its reference A / D conversion are performed by using the margin period after the A / D conversion of the input signal.
By performing the D conversion, the reference data is obtained together with the data of the input signal. Since the reference signal can be used to correct the input signal data such as ratio processing, the measurement accuracy can be further improved.

The reference voltage integration and the reference A / D conversion are performed by integrating the input signal or the A / D conversion thereof.
Since the conversion is performed by utilizing the free time of the integration type A / D conversion unit, the conversion unit can be efficiently used.

According to the integral type A / D converter of claim 3,
Similar to the integral type A / D converter of claim 1, the integrated value of the continuously changing input signal can be measured with high accuracy and based on actual measurement.

In the A / D conversion cycle of the integrated input signal, the ground voltage integration and the ground A / D conversion are performed by utilizing the margin period after the A / D conversion of the input signal. Offset data is obtained together with the data of the input signal. Since the offset data can be used to correct the input signal data such as difference processing, the measurement accuracy can be further improved.

Further, since the ground voltage integration and the ground A / D conversion are carried out by utilizing the free time of the integral type A / D conversion unit which does not carry out the integration of the input signal or the A / D conversion thereof. The parts can be used efficiently.

According to the integral type A / D converter of claim 4,
Similar to the integral type A / D converter of claim 1, the integrated value of the continuously changing input signal can be measured with high accuracy and based on actual measurement.

Further, in the A / D conversion cycle of the integrated input signal, the first reference voltage integration and the first reference A / D conversion are performed by utilizing the margin period after the A / D conversion of the input signal. , The second reference voltage integration and the second reference A / D conversion are performed to obtain the first reference data and the second reference data together with the data of the input signal. By using the first reference data and the second reference data, the input signal data can be corrected by the difference processing, the ratio processing, and the like, so that the measurement accuracy can be further improved.

The first reference voltage integration and first reference A / D conversion, and the second reference voltage integration and second reference A / D conversion perform integration of the input signal or A / D conversion thereof. Not integrated type A /
Since the free time of the D conversion unit is used, the conversion unit can be efficiently used.

According to the integral type A / D converter of claim 5, the A / D conversion data and the additional information (the positive / negative code, the conversion section identification code, the data type code) are output based on a predetermined data format. It is possible to facilitate data transmission and reception processing and prevent troubles.

[Brief description of drawings]

FIG. 1 is an integration type A / D according to a first embodiment of the present invention.
The figure which shows the structure of a converter.

FIG. 2 is an integration type A / D according to the first embodiment of the present invention.
Timing chart of the converter.

FIG. 3 is a configuration diagram of an integral type A / D conversion unit.

FIG. 4 is a timing chart of an integral type A / D converter.

FIG. 5 is an integration type A / D according to a second embodiment of the present invention.
The figure which shows the structure of a converter.

FIG. 6 is an integration type A / D according to a second embodiment of the present invention.
Timing chart of the converter.

FIG. 7 is a data format according to the second embodiment of the present invention.

FIG. 8 is an integration type A / D according to a third embodiment of the present invention.
Timing chart of the converter.

FIG. 9 is an integration type A / D according to a fourth embodiment of the present invention.
Timing chart of the converter.

FIG. 10 is a diagram showing a configuration of a conventional integral type A / D converter.

FIG. 11 is a timing chart of a conventional integral A / D converter.

[Explanation of symbols]

100 0 channel A / D converter 200 1 channel A / D converter 10 integrator 20 control logic means 30 counter 40 register 50 clock pulse generator 60 timing controller SW8 output selector switches SW9, SW9a, SW10, SW10a input selector switch Vin Input signal Iu, Id Constant current Ri Input resistance Ai Amplifier Ci Capacitor Cz Comparator

Claims (5)

[Claims] 1. A first integration type A / D conversion section, a second integration type A / D conversion section, which receives an input signal and outputs the input signal every predetermined period to the first integration type A / D. Input means for alternately supplying to the conversion unit and the second integral A / D conversion unit; A / D conversion data of the input signal converted by the first integral A / D conversion unit; The A / D converted data of the input signal converted by the second integral A / D converter is converted into the first integral A / D converter and the second integral A, respectively.
An output unit for receiving from the / D conversion unit and outputting to the outside, the first integration type A / D conversion unit and the second integration type A
The / D converters each integrate an input signal input during a predetermined period, and A / D-convert the integrated value of the input signal during a subsequent predetermined period. 2. A first integration type A / D conversion section, a second integration type A / D conversion section, which receives an input signal and has a reference voltage,
An input signal is alternately supplied to the first integration type A / D conversion section and the second integration type A / D conversion section every predetermined period, and the second integration is supplied with no input signal. Type A / D converter or input means for supplying the reference voltage to the first integral A / D converter, and A / D of the input signal converted by the first integral A / D converter. Conversion data, A / D conversion data of reference voltage, A / D conversion data of input signal converted by the second integral type A / D conversion unit, A / D of reference voltage
Output means for receiving the converted data from the first integration type A / D conversion section and the second integration type A / D conversion section and outputting the converted data to the outside, respectively. Converter and the second integral type A
Each / D conversion unit integrates the input signal input during a certain predetermined period, performs A / D conversion on the integrated value of the input signal during the subsequent predetermined period, and performs reference voltage integration and reference A / D conversion. An integral type A / D converter characterized by performing. 3. The integration type A / D converter according to claim 2, wherein the reference voltage is a ground voltage, and the offset voltage is obtained by performing ground voltage integration and ground A / D conversion. Integral A / D converter. 4. A first integration type A / D conversion section, a second integration type A / D conversion section, which receives an input signal, has a first reference voltage and a second reference voltage, and has a predetermined period. An input signal is supplied to each of the first integration type A / D conversion section and the second integration type A / D
The voltage is alternately supplied to the conversion unit, and the first reference voltage or the second reference voltage is further alternately supplied to the second integration type A / D conversion unit or the first integration type A / D conversion unit to which the input signal is not supplied. Input means for supplying a second reference voltage, A / D conversion data of the input signal converted by the first integral A / D conversion unit, A / D conversion data of the first reference voltage, and second reference voltage A / D conversion data, A / D conversion data of the input signal converted by the second integral A / D conversion unit, and A / D of the first reference voltage
Output means for receiving the converted data and the A / D converted data of the second reference voltage from the first integration type A / D conversion section and the second integration type A / D conversion section and outputting them to the outside. The first integration type A / D conversion unit and the second integration type A
The / D converters each integrate an input signal input during a predetermined period, A / D-convert the integrated value of the input signal during a subsequent predetermined period, and perform the first reference voltage integration and the first reference A An integration type A / D converter which performs / D conversion or second reference voltage integration and second reference A / D conversion. 5. The integral type A / D converter according to any one of claims 1 to 4, wherein the output means includes, in the A / D converted data, a positive / negative code indicating the content of the data, a conversion section identification code, and a data type code. An integral A / D converter characterized by being output in a predetermined data format with additional information.