TWI387216B - Pulse width digitizing method and pulse width digitizer using thereof - Google Patents

Description

Pulse width signal digitization method and digital device applying the same

The invention relates to a Pulse Width (PW) signal digitizer, and in particular to a PW signal digitizer applying a Sigma-delta modulation algorithm.

In the prior art, Pulse Width (PW) signal modulation and detection technology has been widely known and will be used in many applications. In general, how to detect PW technology with fine resolution is one of the direction that the industry is constantly striving for. Traditionally, many PW detection methods, such as Low Pass Filtering processing methods and Direct-sampling processing methods, have existed. The low pass filtering method operates on the PW information of the Voltage Domain. First, the PW signal is averaged through a low pass filter to find the Direct Current (DC) voltage. A voltage comparator is then applied to compare the DC voltage and the threshold voltage. However, the smoothness of the low-pass filtered pulse width signal affects the resolution of the PW detection. Since the resolution of the PW detection can be improved by increasing the detection period, the user needs to make a trade-off between the resolution and the detection speed of the PW detection when applying the low-pass filtering method.

On the other hand, the direct sampling processing method processes the data in the Time Domain. The PW signal is first subjected to hard limited operation (Hard limited), and then directly sampled by the high frequency reference clock signal to perform PW detection on the PW signal. However, due to insufficient sampling frequency (ie, quantization jitter), the resolution of PW detection is limited by the quantization error in the time domain, and for the direct sampling processing method, the cause Quantization jitter at insufficient sampling frequency is still the main limitation affecting the resolution of PW detection.

Accordingly, how to design a method that can effectively overcome the above-mentioned PW signal modulation and detection method, and effectively realize a high-resolution PW detection method is one of the directions that the industry is constantly striving for.

The invention relates to a pulse width (PW) digitization circuit, which uses a converter to convert an input PW signal into a current signal, and uses a digitizer to generate a digital signal according to the current signal. The PW digitizing circuit of the present invention further applies a feedback path to control the current signal to converge to a specific value in a negative feedback control manner, and accordingly controls the digital signal to be switched between the first digital code (Code) and the second digital code. between. The PW digitizing circuit of the present invention further applies a digital filter to calculate the number of times the digital signal corresponds to the first digit code and the second digit code, and obtains PW information of the PW signal accordingly. In other words, the PW digitizing circuit of the present invention implements a delta-sigma mechanism to implement PW detection of the input PW signal. Therefore, compared with the conventional PW detection method, the PW digitization circuit of the present invention has the advantages of effectively performing PW detection operation with high resolution and good detection speed, and low quantization jitter (Quantization Jitter). .

According to a first aspect of the present invention, a PW digitization system is provided for providing PW information of a PW signal. The PW digitalization system includes a sensor, a current pump, a first capacitor, a digitizer, a first feedback controller, and a digital filter. The sensor is used to provide a PW signal. The current pump is used to provide a current signal in response to the PW signal. The first capacitor is configured to provide a voltage signal in response to the current signal. The digital device is configured to provide a digital signal in response to the voltage signal. The first feedback controller is configured to provide a feedback PW signal in response to the digital signal, wherein the feedback PW signal is selectively fed back to one of the sensor and the current pump to respectively control the PW signal to converge to a specific PW value and The control current signal converges to a specific value, and the digital signal is controlled to be switched between the first digital code (Code) and the second digital code. The digital filter is configured to calculate the number of times the digital signal corresponds to the first digital code and the number of times the digital signal corresponds to the second digital code, and obtain PW information accordingly.

According to a second aspect of the present invention, a PW digitization method is provided for providing PW information of a PW signal. The PW digitization method includes the following steps. First, the PW signal is received at the sensor. The current pump then provides a current signal based on the PW signal. Then provide a voltage signal based on the current signal. Then provide a digital signal according to the voltage signal. Then, in response to the digital signal, a feedback PW signal is provided, wherein the feedback PW signal is selectively fed back to one of the sensor and the current pump to respectively control the convergence of the PW signal to a specific PW value and control the current signal to converge to a specific The value is controlled by the digital signal to be switched between the first and second digit codes. Then, the number of times the digital signal corresponds to the first digital code and the number of times the digital signal corresponds to the second digital code are calculated, and the PW information is obtained accordingly.

According to a third aspect of the present invention, a PW digitizing circuit is provided for providing PW information of a PW signal. The PW digital circuit includes a current pump, a first capacitor, a digitizer, a first feedback controller, and a digital filter. The current pump is used to provide a current signal in response to the PW signal. The first capacitor is responsive to the current signal to generate a voltage signal. The digital device is configured to provide a digital signal in response to the voltage signal. The first feedback controller is configured to provide a feedback PW signal in response to the digital signal, wherein the feedback PW signal is fed back to the current pump to control the current signal to converge to a specific value, and accordingly, the digital signal is switched to the first and the third Between two digit codes. The digital filter is configured to calculate the number of times the digital signal corresponds to the first digital code and the number of times the digital signal corresponds to the second digital code, and obtain PW information accordingly.

In order to make the above-mentioned contents of the present invention more comprehensible, a preferred embodiment will be described below, and in conjunction with the drawings, a detailed description is as follows:

The pulse width (PW) digitization circuit of the embodiment of the present invention applies a delta-sigma mechanism to perform a PW detection operation.

First embodiment

Referring to FIG. 1, a block diagram of a pulse width digitalization circuit in accordance with a first embodiment of the present invention is shown. The PW digitalization system 1 includes a sensor 12, a current pump 14, a capacitor C1, a Quantizer 16, a digital filter 18, and a feedback controller 20.

The sensor 12 is configured to provide a PW signal PW _in to be measured by the PW information. Please refer to FIG. 2, which is a detailed block diagram of the sensor 12 of FIG. For example, the PW digitization system 1 is applied to a communication application, and the sensor 12 is implemented by a Super Regenerative Receiver to receive a Radio Frequency (RF) signal, and the PW signal is received. PW _{in is} used to indicate the input power value of the RF signal. For example, the sensor 12 includes an antenna 12a, a Low Noise Amplifier 12b, an oscillator 12c, an Envelope Detector 12d, a Limiter 12e, and a current source 12f. The antenna 12a receives the RF signal RF _in , and the RF signal RF _{in is} then amplified by the low noise amplifier 12b and supplied to the oscillator 12c. For example, the RF signal RF _in is an Amplitude-shift Keying (ASK) signal.

Drive current oscillator 12c is provided a current source 12f I _dr driven in response to the RF signal RF _in to generate the oscillation signal OSC. The oscillating signal OSC is provided to the envelope detector 12d and the limiter 12e to find the PW information of the PW signal PW _in by finding the envelope information of the oscillating signal OSC. For example, after the drive current I _dr is enabled, the oscillator 12c needs a start time (Startup Time) to start generating the oscillation signal OSC, and the length of the start time is substantially inversely proportional to the RF signal RF _in The power is shown in Figure 3.

When the RF signal RF _in corresponds to a low power value, the start time of this segment corresponds to the period T _stupl . When the RF signal RF _in corresponds to a high power value, the start time of this segment corresponds to the period T _stuph . The PW information PW _h and PW _l corresponding to the PW signal PW _in meet the following conditions:

PW _l =TQ-Td-T _stupl

PW _h =TQ-Td-T _stuph

Where Td is the preset reset time (Reset Time); TQ is the length of a period of operation, which is defined as the fixed length of time between two adjacent reset time points RST. Thus, having a length corresponding to the starting point via the specified period of time _in PW PW signal, it can be efficiently used to obtain the input power PW PW signal indicating the value of the RF signal RF _{in in.}

Please refer to FIG. 4, which is a detailed block diagram of the current pump 14 of FIG. Current pump 14 provides a current signal I _in response to the signal PW PW _in. For example, current pump 14 includes current sources 14a and 14b that are coupled to node ND. Current pump 14 is connected to capacitor C1 via node ND. The current source 14a is turned on _in response to the enable level PW signal PW _in to provide the drive current I _dr21 and is turned off in response to the non-enable level PW signal PW _in .

The current source 14b is turned on in response to the reference PW signal PW _ref to provide a driving current I _dr3 , wherein the reference PW signal PW _ref corresponds to a fixed PW value. The difference between the drive currents I _dr2 and I _dr3 is used to determine the current signal I _in . Capacitor C1 by the current signal I _in charge, _in response to a voltage signal corresponding to the current signal V _in to I.

During each operation period TQ, the digital device 16 generates a digital signal V _{QT in} response to the voltage signal V _in . For example, the digital signal V _QT is a bit signal of a bit. When the voltage signal V _{in is} greater than a threshold voltage, the digital signal V _QT corresponds to the value 1; when the voltage signal V _{in is} less than the threshold value, the digital signal V _QT corresponds to the value 0.

The feedback controller 20 generates a feedback PW signal PW _fb in response to the digital signal V _QT modulation. The feedback PW signal PW _{fb is,} for example, _fed back to the sensor 12 to control the PW signal PW _in . In an example, the feedback controller 20 can implement the PW subtraction operation on the PW signal PW _in via the modulation Rising Edge time of the PW signal PW _fb , and implement the PW signal PW _{in accordingly} . Negative feedback control, thereby controlling the PW signal PW _in , the current signal I _in and the voltage signal V _{in to} converge to their corresponding specific values, and controlling the digital signal V _{QT to be} switched between the first and second digit codes. Thus, through the circuit operation of the PW delta integration, the digital filter 18 can determine the PW information of the PW signal PW _{in in} response to the digital signal V _QT . Next, the aforementioned PW subtraction operation, PW negative feedback control operation, and PW triangular integration operation will be further described.

Please refer to FIGS. 5A and 5B , which are related timing diagrams of the sensor 12 of FIG. 1 . In one example, the operational period TQ can be equally divided into sub-periods 1 ^st -T _s , 2 ^nd -T _s , 3 ^rd -T _{s ,} and 4 ^th -T _s . When the digital signal V _QT corresponds to the value 0, the rising edge of the feedback PW signal PWfb is triggered at the time point ST1, that is, the boundary time between the sub-phases 1 ^st -T _s and 2 ^nd -T _s , as shown in FIG. 5A Show. Under such conditions, the PW value D _{x of the} PW signal PW _in remains in a state in which the subtraction operation is not performed.

When the digital signal V _QT corresponds to the value 1, the rising edge of the feedback PW signal PW _fb is triggered at the time point ST2, that is, the boundary time between the sub-periods 2 ^nd -T _s and 3 ^rd -T _s , as shown in FIG. 5B Shown. In other words, the rising edge of the feedback PW signal PW _fb is delayed by a sub-period T _s (that is, the sub-period 2 ^nd -T _s ) compared to the operation performed when the digital signal V _QT corresponds to the value 0. Thus, the operation of supplying the drive current I _dr1 (executed by the drive current source 12f) and the operation of generating the oscillation signal OSC (executed by the oscillator 12c) are delayed by a sub-period T _s , and the PWD _{x of the} PW signal PW _in will be Correspondingly, the sub-period T _s is subtracted (ie, reduced). In this way, the sensor 12 can be controlled by the feedback controller 20 to modulate the PW signal PW _in such that the PW signal PW _in corresponds to its original PW value D _x or to the PW value D _x -T _s .

Please refer to FIG. 6 , which is a timing diagram of related signals corresponding to the first to third figures. By performing the PW subtraction operation, negative feedback control can be implemented on the PW signal PW _in to control the PW signal PW _{in to} converge to a specific PW value. For example, this particular PW value is a constant and is equal to a multiple of the sub-period T _s . Since the signal PW PW _in particular the convergence point value PW, PW signal PW _in accordance with the current signal I _in is generated and the voltage signal V _in will also converges to a certain value of its corresponding. In one example, by setting the reference PW signal PW _ref to a multiple of the sub-period Ts, the current sources 14a and 14b will be controlled by PW signals having substantially the same PW value to correspondingly generate substantially equal drive currents. I _dr2 and I _dr3 ; in other words, the current signal I _in and the voltage signal V _in will converge to a zero current value and a zero voltage value, respectively.

As described in the preceding paragraphs, the sensor 12, the current pump 14, the digitizer 16, and the feedback controller 20 can implement a negative feedback loop. Thus, the digital signal V _QT will be continuously switched between the digital code 1 and 0. The digital filter 18 calculates the number of times the digital signal V _QT corresponds to the digital code 1 and the number of times the digital signal V _QT corresponds to the digital code 0 during a sampling period T _DATA to correspondingly obtain the PW information of the PW signal PW _in . The aforementioned sampling period T _DATA corresponds, for example, to an operation period T _{Q of} 8 times as shown in FIG. In this way, the trigonometric integral modulation operation can be effectively performed to find the PW information of the PW signal PW _in and the input power of the RF signal RF _in .

In the embodiment, the case where the PW digitizing system 1 is applied to the communication application in cooperation with the super regenerative receiver is taken as an example. However, the PW digitizing system 1 of the embodiment of the present invention is not limited thereto. And can be applied to other areas of operation.

In the embodiment, the case where the sensor 12 in the PW digitizing system 1 is a super regenerative receiver is taken as an example. However, the sensor 12 in the PW digitizing system 1 of the embodiment of the present invention is It is not limited to this, but can be implemented by other sensors with PW signal output.

The PW digitization system of the embodiment of the invention applies a converter to convert the input PW signal into a current signal; the digitizer generates a digital signal according to the current signal; and the feedback path controls the current signal to converge to a specific manner in a negative feedback control manner. a value, and according to the control digital signal is switched between the first digital code (Code) and the second digital code; the digital filter calculates the number of times the digital signal corresponds to the first digital code and the second digital code, and accordingly PW information of PW signal. In other words, the PW digitization circuit of the embodiment of the present invention implements a triangular integration mechanism to implement PW detection of the input PW signal. Thus, the PW digitization circuit of the embodiment of the present invention has the advantages of effectively performing PW detection operation with high resolution and good detection speed, and lowering quantization jitter, compared to the conventional PW detection method.

Second embodiment

The PW digitization system of the second embodiment of the present invention applies another different feedback controller loop to perform the feedback control operation. Referring to FIG. 7, a block diagram of a pulse width digitalization system in accordance with a second embodiment of the present invention is shown. The PW digitization system 2 of the embodiment of the present invention is different from the digitization system of the first embodiment in that the feedback PW signal PW _fb is fed back to the current pump 24 instead of being fed back to the sensor 22. In the present embodiment, the current pump 24, the digitizer 26, the digital filter, and the feedback controller 30 form a PW digitizing circuit 20 to perform a PW-to-digital conversion operation.

Please refer to FIG. 8 , which is a detailed block diagram of the sensor 22 of FIG. 7 . In the second embodiment, the PW signal PWin is not modulated, and an additional drive controller (Quench Controller) 22g is further applied to provide the voltage signal V _Q drive current source 22f. The voltage signal V _Q has a fixed rising edge which is triggered at the demarcation point of the sub-periods 1 ^st -T _s and 2 ^nd -T _s .

Please refer to FIG. 9, which is a detailed block diagram of the current pump 24g of FIG. The PW digitizing system 2 of the second embodiment applies a current pump 24, wherein unlike the current pump 14 of the first embodiment, the current pump 24 has a current source 24b controlled by the feedback PW signal PW _fb instead of The current pump 14 as in the first embodiment has a current source 14b controlled by a reference PW signal PW _ref . Current source 24b by the feedback line drive signal PW PW _FB to provide a drive current of I _dr4, wherein the driving current and the current source I _dr4 24a provided corresponding to the driving current I _dr2 to substantially the same current value. Thus, as in the first embodiment, the current signal Iin by the PW digital modulation system of a general, the current signal Iin decided by the Department of the drive current I _dr2 I _dr4 converges to zero and the current value. In this way, although there are different feedback paths, a negative feedback control loop similar to that described in the first embodiment can be implemented to perform a similar triangular integration operation.

In the present embodiment, the case where the PW digitizing circuit 20 has the circuit configuration as shown in FIG. 7 is taken as an example. However, the PW digitizing circuit 20 is not limited thereto, and other different circuit structures may be used. to realise.

In the present embodiment, although only the PW digitizing circuit 20 is applied to the PW digitizing system 2 including the sensor 22 implemented by the super regenerative receiver, the PW digit conversion operation is performed for the PW signal PW _in The case is described as an example. However, the PW digitizing circuit 20 is not limited thereto, and is more applicable to other applications that perform a PW-to-digital conversion operation.

The PW digitization system of the embodiment of the invention applies a converter to convert the input PW signal into a current signal; the digitizer generates a digital signal according to the current signal; and the feedback path controls the current signal to converge to a specific manner in a negative feedback control manner. a value, and according to the control digital signal is switched between the first digital code (Code) and the second digital code; the digital filter calculates the number of times the digital signal corresponds to the first digital code and the second digital code, and accordingly PW information of PW signal. In other words, the PW digitization circuit of the embodiment of the present invention implements a triangular integration mechanism to implement PW detection of the input PW signal. Thus, the PW digitization circuit of the embodiment of the present invention has the advantages of effectively performing PW detection operation with high resolution and good detection speed, and lowering quantization jitter, compared to the conventional PW detection method.

Third embodiment

The PW digitization system of the second embodiment of the present invention is implemented by applying another different circuit structure. Referring to FIG. 10, a block diagram of a pulse width digitizing circuit in accordance with a third embodiment of the present invention is shown. The PW digitizing circuit 20' is different from the PW digitizing circuit in the foregoing embodiment in that it further applies an integrator 35 and another feedback controller 40 to perform a second-order feedback control operation.

The feedback controller 40 is configured to modulate the feedback current signal I _fb in response to the digital signal V _QT . The feedback controller 40 returns the feedback current signal I _fb to the integrator 35. The integrator 35 is as shown in Fig. 11, and includes a transconductor 35a, an adder 35b, and a capacitor C3. Transducer 35a generates a current signal I _s via the operation according to the voltage signal V _in. The adder 35b generates a difference signal according to the difference current I _s and the feedback current I _fb of the signal I _d. Capacitor C3 is used to integrate the difference I _d to generate a filtered voltage signal V' _in . The filtered voltage signal V' _in is provided to the digital device 36 to correspondingly generate the digital signal V _QT . As such, the PW digitizing circuit 20' can be configured with a second-order high-pass filtering function (ie, the integrator 35) for quantization noise shaping, instead of having only a first-order high-pass as in the foregoing embodiment. PW digitization circuit for filtering function.

The PW digitization system of the embodiment of the invention applies a converter to convert the input PW signal into a current signal; the digitizer generates a digital signal according to the current signal; and the feedback path controls the current signal to converge to a specific manner in a negative feedback control manner. a value, and according to the control digital signal is switched between the first digital code (Code) and the second digital code; the digital filter calculates the number of times the digital signal corresponds to the first digital code and the second digital code, and accordingly PW information of PW signal. In other words, the PW digitization circuit of the embodiment of the present invention implements a triangular integration mechanism to implement PW detection of the input PW signal. Thus, the PW digitization circuit of the embodiment of the present invention has the advantages of effectively performing PW detection operation with high resolution and good detection speed, and lowering quantization jitter, compared to the conventional PW detection method.

In view of the above, the present invention has been disclosed in several preferred embodiments, and is not intended to limit the invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

1, 2. . . Pulse width digitalization system

12, 22. . . Sensor

14, 24, 24'. . . Current pump

16, 26, 26'. . . Digital device

18, 28, 28'. . . Digital filter

20, 30, 30', 40. . . Feedback controller

C1, C2, C2'. . . capacitance

12a, 22a. . . antenna

12b, 22b. . . Low noise amplifier

12c, 22c. . . Oscillator

12d, 22d. . . Envelope detector

12e, 22e. . . Limiter

12f, 14a, 14b, 22f, 24a, 24b. . . Battery

ND. . . node

20, 20'. . . Pulse width digitalization circuit

22g. . . Drive controller

35. . . Integrator

35a. . . Transducer

35b. . . Adder

1 is a block diagram of a pulse width digitalization circuit in accordance with a first embodiment of the present invention.

FIG. 2 is a detailed block diagram of the sensor 12 of FIG.

Figure 3 is a timing diagram of the related signals in Figure 2.

Fig. 4 is a detailed block diagram of the current pump 14 of Fig. 1.

5A and 5B are related timing diagrams of the sensor 12 of FIG. 1 .

Figure 6 is a timing diagram of the correlation signal corresponding to the first to third figures.

Figure 7 is a block diagram showing a pulse width digitalization system in accordance with a second embodiment of the present invention.

FIG. 8 is a detailed block diagram of the sensor 22 of FIG. 7.

Fig. 9 is a detailed block diagram of the current pump 24g of Fig. 7.

Figure 10 is a block diagram showing a pulse width digitalization circuit in accordance with a third embodiment of the present invention.

Fig. 11 is a detailed block diagram of the integrator 35 of Fig. 10.

Claims (16)

A pulse width (PW) digitization system for providing PW information of a PW signal, the PW digitization system comprising: a sensor for providing the PW signal; and a current pump (Current Pump Providing a current signal in response to the PW signal; a first capacitor for providing a voltage signal in response to the current signal; and a Quantizer for providing a digital signal in response to the voltage signal; a first feedback controller for providing a feedback PW signal in response to the digital signal, wherein the feedback PW signal is fed back to the sensor or the current pump to respectively control the PW signal to converge to one a specific PW value and controlling the current signal to converge to a specific value, and controlling the digital signal to be switched between a first digital code (Code) and a second digital code; and a digital filter for calculating the The number of times the digital signal corresponds to the first digital code and the number of times the digital signal corresponds to the second digital code, and the PW information is obtained accordingly. The PW digitization system of claim 1, wherein the current pump comprises: a node coupled to the first capacitor; and a first current source coupled to the node for responding to the The PW signal selectively provides a first drive current through the node and the first capacitor. For example, the PW digitalization system described in claim 2, The current pump further includes: a second current source coupled to the node for selectively providing a second driving current in response to the feedback PW signal, the difference between the first and second driving currents Used to determine the current signal that converges to the particular value. The PW digitization system of claim 2, wherein the sensor comprises: an antenna for receiving a radio frequency (RF) signal; and an oscillator receiving a second driving current to And generating a second driving current in response to the feedback signal, wherein the second driving current is generated in response to the feedback signal; wherein the enabling time of the feedback PW signal and the second driving current are The enabling time is determined according to the digital value, so that the operation of generating the PW signal in response to the RF signal can be selectively delayed to achieve the PW subtraction operation on the PW signal, and the negative feedback control is performed. The PW signal converges to the specific PW value. The PW digitization system of claim 4, wherein the current pump further comprises: a third current source coupled to the node to selectively provide a third driving current in response to a predetermined PW signal. The difference between the first and the third driving currents is used to determine the current signal that converges to the specific value. The PW digitization system of claim 4, wherein the sensor is a Super Regenerative Receiver. The PW digitizing system of claim 1, further comprising: a second feedback controller for providing a feedback current signal in response to the digital signal; and an integrator for inputting the The voltage signal is processed by the digital device, the integrator includes: a transconductor for generating a conversion signal according to the voltage signal; and an adder for obtaining the conversion signal and the feedback current signal a differential current; and a second capacitor for determining a filtered voltage signal according to the difference current, and providing the filtered voltage signal to the digitizer, wherein the digitizer determines the signal in response to the filtered voltage signal Digital signal. A pulse width (PW) digitization method for providing PW information of one PW signal, the PW digitization method includes: receiving the PW signal at a sensor; and a current pump (Current Pump) Providing a current signal according to the PW signal; providing a voltage signal according to the current signal; providing a digital signal according to the voltage signal; and providing a feedback PW signal in response to the digital signal, wherein the feedback PW signal is fed back to The sensor or the current pump controls the PW signal to converge to a specific PW value and controls the current signal to converge to a specific value, and accordingly controls the digital signal to switch to a first digital code (Code) and Between a second digit code; Calculating the number of times the digital signal corresponds to the first digital code and the number of times the digital signal corresponds to the second digital code, and obtaining the PW information accordingly. The PW digitization method of claim 8, wherein the step of providing the current signal further comprises: generating a first driving current in response to the PW signal; generating a second driving current in response to the feedback PW signal And determining the current signal that converges to the specific value is the difference between the first and second driving currents. The PW digitization method of claim 8, wherein the step of receiving the PW signal by the sensor further comprises: generating the PW signal according to a radio frequency (RF) signal, wherein the PW signal is generated. The step is caused by a first driving current; the uniform driving time of the first driving current is set according to the digital signal to modulate the first driving current, so that the operation of generating the PW signal in response to the RF signal can be performed. Optionally, the operation is delayed to achieve PW subtraction of the PW signal, and the PW signal is converged to the specific PW value via negative feedback control. The PW digitization method of claim 10, wherein the step of providing the current signal further comprises: generating a second driving current in response to the PW signal converging to the specific PW value; and responding to a preset The PW signal generates a third driving current, and the difference between the first driving current and the third driving current is used to determine convergence to the specific PW value. The current signal. The PW digitization method according to claim 8, wherein the sensor is a Super Regenerative Receiver. A pulse width (PW) digitization circuit for providing PW information of a PW signal, the PW digit circuit comprising: a current pump for providing a current signal in response to the PW signal a first capacitor for generating a voltage signal in response to the current signal; a Quantizer for providing a digital signal in response to the voltage signal; a first feedback controller for responding to the signal The digital signal provides a feedback PW signal, wherein the feedback PW signal is fed back to the current pump to control the current signal to converge to a specific value, and accordingly, the digital signal is controlled to be switched to a first digital code (Code) And a second bit code; and a digital filter for calculating the number of times the digital signal corresponds to the first digital code and the number of times the digital signal corresponds to the second digital code, and obtaining the PW information. The PW digitizing circuit of claim 13, wherein the current pump comprises: a node coupled to the first capacitor; and a first current source coupled to the node for responding to the The PW signal selectively provides a first drive current through the node and the first capacitor. The PW digitizing circuit of claim 14, wherein the current pump further comprises: a second current source coupled to the node for selectively providing a second in response to the feedback PW signal The driving current, the difference between the first and the second driving currents is used to determine the current signal that converges to the specific value. The PW digitizing circuit of claim 13 further comprising: a second feedback controller for providing a feedback current signal in response to the digital signal; and an integrator for inputting the The voltage signal is processed by the digital device, the integrator includes: a transconductor for generating a conversion signal according to the voltage signal; and an adder for obtaining the conversion signal and the feedback current signal a differential current; and a second capacitor for providing a filtered voltage signal according to the difference current, and providing the filtered voltage signal to the digitizer, wherein the digitizer determines the signal in response to the filtered voltage signal Digital signal.