CN201995160U - Control chip of light emitting diode (LED) power supply - Google Patents

Abstract

The utility model relates to an LED power supply control chip, in which a signal measurement module is connected with a sampling control module, the sampling control module is respectively connected with a sample comparator, a volatile memory, and a PWM module, the sample comparator is connected with a nonvolatile memory, and the volatile memory It is connected with the PWM module, the non-volatile memory is connected with the PWM module, the 24-hour cycle counter is connected with the time comparator, the time comparator is connected with the non-volatile memory, and the PWM module, the clock frequency division module is connected with the 24-hour cycle counter, and the chip address The module is connected to the volatile memory, the communication interface is connected to the volatile memory, the communication interface is connected to the 24-hour cycle counter, the communication interface is connected to the non-volatile memory, the LED parallel branch open circuit number adder is connected to the PWM module and the volatile memory, The utility model can simply realize analog-to-digital conversion without embedding an analog circuit in the chip, so as to reduce the cost as much as possible, and the chip can be used alone or in a network.

Description

LED power control chip

technical field

The utility model relates to the technical field of chips, in particular to an LED power supply control chip.

Background technique

The driving of LED mainly adopts the constant current source controlled by PWM. The existing LED power supply control generally provides the temperature detection function, but the temperature compensation generally only controls the limit temperature, and the method of turning off the power supply or PWM without output is adopted. , for over-current protection, it only detects the total power supply current of the total constant current source to adjust the PWM output; it does not consider changing the given power output power through ambient light or condition parameters, because this is not called constant Current source; it does not consider the open circuit of the parallel branch of the LED. When the parallel branch of the LED is open, the current will be added to the remaining normal branch. In this way, the normal parallel branch will share the total current, which is likely There will be an avalanche of rapid damage to the LED.

For the case of mains power supply, sometimes there is a requirement for peak and valley adjustment of power supply, or artificial power adjustment, so it is necessary to set timing operation parameters. The existing LED power supply driver chip does not have such a function. In all cases, it is possible to use a microprocessor (MCU), but the price will increase a lot. Not only must the microprocessor be embedded in the chip, but also the processor architecture, analog-to-digital converter, communication interface, non-easy Lost memory and microprocessor programming language system, due to the board-level technology used, the reliability will not be very high, the cost will be relatively high, and the working clock frequency is limited by the microprocessor (MCU) used, the user's The use of technology also has higher requirements, and the development of low-cost, powerful LED power supply control chips has always been the goal pursued by the industry.

Contents of the invention

The problem to be solved by the utility model is to provide a LED power supply control chip with strong functionality and low cost. This power supply chip is a digital chip. . The utility model solves the safety problem when the LED parallel branch circuit is broken, and solves the operation problem when the LED lamp needs timing and setting parameters. At the same time, the chip of the utility model provides a programmable address, which can be controlled by a remote host Run it online.

In order to solve the above technical problems, the utility model adopts the following technical solutions:

An LED power supply control chip is characterized in that it includes: a signal measurement module, a sampling control module, a communication interface, a sample comparator, a clock and a frequency division module, a chip address module, a volatile memory, a nonvolatile memory, and a 24-hour cycle Counter, LED parallel branch open circuit number adder, time comparator, PWM module, signal measurement module and sampling control module are connected to establish a sampling channel and obtain sampling data; the sampling control module is respectively connected to the sample comparator, volatile memory, The PWM module is connected, the sample comparator is connected with the non-volatile memory, and the sample data from the non-volatile memory is compared and the result is saved in the volatile memory, the volatile memory is connected with the PWM module, and the sampling control module controls the ambient brightness The value is compared with the current value saved in the volatile memory. If the ambient brightness value changes, the sampling control module will send an ambient brightness change signal to the PWM module; the sampling control module will compare the measured temperature value with the non-volatile memory at the same time. If it is not within the normal temperature range, the sampling control module sends a temperature abnormal signal to the PWM module, the non-volatile memory is connected to the PWM module, and the PWM module extracts the parameters stored in the non-volatile memory, 24-hour cycle The counter is connected to the time comparator, and the time comparator is connected to the non-volatile memory and the PWM module. The time comparator is used to compare with the timing value from the non-volatile memory. When a timing start or timing end signal occurs, the time The comparator will start the connection with the PWM module to start the PWM calculation based on this condition; the clock frequency division module is connected with the 24-hour cycle counter, the chip address module is connected with the volatile memory, and the chip address is stored in it, and the communication interface is connected with the easy The communication interface is connected with the 24-hour cycle counter to start the correction time, and the communication interface is connected with the non-volatile memory to set, modify or receive parameters. The LEDs are connected in parallel The open circuit number adder is connected with the PWM module and the volatile memory, and performs carry addition operation on the parallel open circuit status of all LED branches. If the LED parallel branch is abnormal, the result of the carry addition operation is sent to the volatile memory and sent to the The PWM module transmits the abnormal signal of the LED parallel branch.

Compared with the prior art, the utility model has the following beneficial effects: each module of the utility model has the characteristics of real-time operation, cancels the method of embedding a microprocessor, and reduces the cost of purchasing intellectual property rights, and the utility model can be easily realized Analog-to-digital conversion does not need to embed analog circuits in the chip to reduce the cost as much as possible. The chip can be used alone or in a network, which greatly improves and enhances the existing The function of the LED power control chip and the safety protection of the LED. The utility model has smooth dimming according to the brightness of the environment; smooth dimming and over-temperature protection in the warning range of temperature; can realize timing and conditional operation; and is suitable for remote network control with different lighting brightness requirements.

Description of drawings

Figure 1 is a chip module diagram

Figure 2 is the chip pin diagram

Figure 3 is a diagram of the signal measurement module

Figure 4 is a diagram of the backup battery charging module, clock and frequency division module, and 24-hour cycle counter module

Figure 5 is a diagram of the communication interface and chip address module

Figure 6 is a schematic diagram of the PWM module.

Detailed ways

Referring to Figure 1, the utility model includes a signal measurement module, a backup battery charging module, a communication interface, a sampling control module, a sample comparator, a clock and a frequency division module (that is, a clock generation module and a multi-channel frequency division module), a chip address module, Volatile memory, non-volatile memory, 24-hour cycle counter, LED parallel branch open circuit number adder, time comparator, PWM module. The connection relationship of each module is as follows:

1) The signal measurement module is connected to the sampling control module to establish a sampling channel and obtain sampling data; the measured objects are ambient brightness signals, temperature signals and LED parallel branch circuit break signals input in the form of digital I/O for multiple channels , including two-channel resistance comparison method to measure temperature and ambient brightness, and a signal measurement method using RC discharge circuit discharge time sampling, the temperature measurement circuit is built into the chip;

2) The sampling control module is connected to the sample comparator, volatile memory, and PWM module respectively, the sample comparator is connected to the non-volatile memory, and the chip has a built-in non-volatile memory to compare with the sample data from the non-volatile memory and The obtained result is stored in the volatile memory, and this result will still be used as the parameter of the calculation in the sampling control module. According to the calculation result, it is determined whether to send the ambient brightness change signal or the abnormal temperature signal to the PWM module. The current value in the volatile memory is compared, and if there is a change, the sampling control module will send an ambient brightness change signal to the PWM module; the sampling module will compare the measured temperature value with the set value in the non-volatile memory at the same time, If it is not within the normal temperature range, the sampling control module sends an abnormal temperature signal to the PWM module. The volatile memory is connected to the PWM module, and saves the count value used by the PWM period counter and the PWM pulse width counter of the PWM module;

3) The chip has a built-in PWM module, the calculation function of the PWM module; it includes the calculation of priority determination, the calculation of ambient brightness and PWM duty cycle, the calculation of temperature adjustment, the calculation of PWM duty cycle determined by the total number of open circuits of LED parallel branches, Calculate the PWM duty cycle during the set running period. The PWM module contains two counters, one for pulse cycle counting and one for pulse width counting to generate PWM pulses. The PWM duty cycle corresponds to these two counters count value;

4) The backup battery charging module has a charging circuit. The backup battery charging module is connected to the clock frequency division module to obtain the correct clock. The clock frequency division module is connected to the 24-hour cycle counter; the dual power supply supplies power to the chip, and the main power supply is powered off. The battery is always powered by the chip to ensure the operation of the 24-hour cycle clock, the data storage of the non-volatile memory and the restart of the chip, and there is no need to switch between the two power sources, thereby ensuring its reliability;

5) The 24-hour cycle counter is connected to the time comparator, and the time comparator is connected to the non-volatile memory and the PWM module. The time comparator is used to compare with the timing value (start or end point) from the non-volatile memory, and then compare it with the PWM The modules are connected, when there is a timing start or timing end signal, the time comparator will start the connection with the PWM module to start the PWM calculation based on this condition;

6) The non-volatile memory is connected to the PWM module in order to extract several parameters stored in it (safety temperature maximum value, limit temperature value, timing start and end point, set working parameters (such as set working voltage or environment) Brightness parameter);

7) The chip address module is connected to the volatile memory, and the chip address is stored in it; the chip provides 4 pins for setting the chip address, and 15 different addresses can be formed by connecting the positive pole of the power supply and the ground;

8) The communication interface is connected to the volatile memory to retrieve the chip address to the remote host, and save the time value to be calibrated in it, and the chip has a built-in communication interface;

10) The communication interface is connected with the 24-hour cycle counter to start the correction time;

11) The communication interface is connected to the non-volatile memory for setting, modifying or receiving parameters;

12) The LED parallel branch open circuit number adder is connected with the PWM module and the volatile memory. The LED parallel branch circuit open circuit number adder performs carry addition operation on the parallel open circuit status of all LED branches. If the LED parallel branch circuit is abnormal, Send the result of the carry addition operation to the volatile memory, and send the abnormal signal of the LED parallel branch to the PWM module.

Referring to Fig. 2, the chip body 100 has 24 pins: main power supply pin VCC, backup battery power supply pin VCC1, ground wire GND, two clock pins XTAL0 and XTAL1, two communication interface pins RX and TX, 4 1 address programming pin A0～A3, 2 resistance comparison sampling pins X0 and X1, 3 RC charge and discharge sampling pins B0～B2, 6 LED parallel branch circuit break feedback signal pins IO-0～IO-5 . The open circuit number adder of the LED parallel branch connects the level signal of the voltage sampling of the LED parallel branch through the chip pins IO-0-IO-5, and judges the sum of the open circuits of the LED parallel branch.

Referring to Fig. 3, Fig. 3 is a diagram of a signal measurement module.

1) Acquisition of the temperature signal, the chip has 3 built-in resistors, one is a standard precision resistor RS, one is a thermistor RT, and the other is a conventional resistor R, RS and R are connected to the data sampling control module 106 through the on-off control module 105, After the thermistor RT is connected with the strobe switch 104, it is connected with the data sampling control module 106 through the on-off control module 105, and the other ends of the three resistors are connected together, and then connected with an off-chip capacitor C1, The other end of C1 is grounded. The measurement principle is: connect the standard precision resistor RS through the on-off control module 105 and set the high level, connect R and set the platform low, RS will charge C1, and connect to the level of R to the data sampling control module 106 When it becomes high, it indicates that the capacitor C1 is fully charged. The standard precision resistor RS is disconnected through the on-off control module 105, and the connection line of R is set to a low level. The capacitor C1 will discharge through the resistor R, thereby determining a standard for charging through RS. charging time. The thermistor RT is the same as the standard precision resistor RS, and the same action can also be used. When the thermistor changes, the charging time of the capacitor C1 will also change, corresponding to the charging time of the standard precision resistor, you can get The value of the thermistor is obtained to obtain the value of temperature.

) Obtain ambient light signals by measuring resistance, such as measuring photosensitive resistor or photodiode resistance RL, the principle of temperature measurement can be used, but the placement of the measured resistance object is related to the environment, so it can only be placed outside the chip, RL After being connected with the gate switch 104 in the chip, it is connected with the data sampling control module 106 through the on-off control 105 . The gating switch 104 determines when to measure the temperature signal and when to measure the ambient light signal to realize two-channel measurement.

) to measure the ambient light by measuring the RC charge and discharge time, and to measure the ambient light by measuring the RC discharge time is another optional analog signal measurement method. 101 is connected to the resistor R1, and then connected to the charging capacitor C2, the inverting terminal of the comparator 102, and the non-inverting terminal of the comparator 103, and the inverting terminal of the comparator 103 is grounded to form a zero comparator. The reference voltage Vf is connected to the non-inverting terminal of the comparator 102 , the output of the comparator 102 is connected to the pin B0 of the chip, and this pin is connected to the sampling control module 106 . The output of the comparator 103 is connected to the pin B1 of the chip, and this pin is connected to the sampling control module 106 . The gating signal line of the gating switch 101 is connected to the sampling control module 106 through the chip pin B2. The measurement principle is: when the gate switch is connected to one side of V(t), the capacitor C2 starts to be charged, and when it is charged to the reference voltage Vf, the comparator 102 outputs an inversion signal, and at this time the gate switch 101 is connected to At the ground terminal, the capacitor C2 starts to discharge, and when the discharge is over, the comparator 103 gives a signal, at this time the strobe switch 101 is connected to V(t), and charging starts. As long as the discharge time is recorded, the value of V(t) can be obtained according to the formula: Vf=V(t)*e ^-t/RC . Then, corresponding to the standard quantization recording table in the on-chip memory, the sampling of the analog signal can be completed. It should be emphasized that the value of V(t) can also be obtained by measuring the time when the charging C2 voltage reaches Vf. Although V(t) is a function of time, as long as Vf, R1 and C2 are properly selected, the charging The discharge time is short enough to obtain good accuracy of V(t).

The data sampling process , its functions include: 1) Connect the non-volatile memory 110 with the determined standard quantization value of the sample. This data cannot be lost and can be rewritten through the communication interface programming. This memory needs to be non-volatile, and the sampling control Modules are read-only. 2) When the resistance comparison method is used for sampling, control channel switching when sampling the temperature signal and the ambient light signal, determine the sampling interval, and control the on-off control module 105 . 3) The two sampling methods described in the right require testing the charging or discharging time of the capacitor C1 or C2, and compare the look-up table with the standard quantized value stored in the non-volatile memory 110, if the data falls within the determined Within the scope, then the data is sent to the volatile memory 107, if what sampled is the ambient brightness signal, then compare with the ambient brightness value of the currently determined PWM signal, if it is different, the ambient brightness change signal connected to the PWM module will be started; if The temperature signal is sampled, and compared with the set value in the non-volatile memory, if it is not within the normal range, an abnormal temperature signal connected to the PWM module will be activated. The output driving module 111 drives and amplifies the PWM signal and then outputs it.

The method of judging the disconnection of multiple LED parallel branches is to sample the voltage of each LED parallel branch and set it as a level signal. When there is a voltage signal, it is high level, and when there is no voltage signal, it is Low level, at this time, it indicates that a certain LED parallel branch has been disconnected. These signals are connected to the LED parallel branch disconnection number adder 108 through the pins of the chip, which is a function that can be realized by a simple carry adder. When all branches are at high level, the sum has a maximum value, so it can be determined whether there is an open circuit in the LED branch. Once the sum is not the maximum value, the PWM meter module 109 will be triggered by the abnormal signal of the LED parallel branch connected to the PWM module, and the PWM calculation will be made according to the disconnection number.

Figure 4 is a circuit diagram of a backup battery charging module, a clock and a frequency division module, and a 24-hour cycle counter. The main power supply VCC is connected to the non-inverting terminal of the comparator 201 through a resistor R2. The resistor R4 is connected to the base of the triode Q, the emitter of Q charges the battery BT through the diode D2, the collector of Q is connected to the main power supply VCC through the diode D1, the emitter of Q is connected to the ground through the capacitor C3, and the emitter of Q It is connected to the resistor R6, and then connected to the ground through R7, the base of Q is connected to the ground through the resistor R5, the emitter of Q is connected to the resistor R6, and then connected to the inverting terminal of the comparator 201 to obtain a feedback signal.

Its working principle is: VCC is divided by R2 and R3 to obtain a reference voltage value as the comparison reference of the comparator 201 . Then the comparator 201 outputs a signal to the triode Q, and the triode selects the switching tube to work in the switching state, and then can charge the rechargeable battery BT. D1 has the function of voltage regulation. When charging, the feedback voltage signal will increase, and when it reaches the reference voltage, the comparator will have no output, and the triode will stop working. BT batteries will not be charged. When the feedback voltage signal is low enough, the backup battery BT will be charged again.

The backup battery BT provides power VCC1 for the clock generation module 202 , the multiplex frequency division module 203 , the 24-hour cycle counter 204 , the nonvolatile memory 110 , and the power-off restart timer 207 in the chip. Except that other modules in the chip are powered by the main power supply VCC, which can ensure that the backup battery works without switching after the main power supply VCC is powered off. The clock generation module 202 and the multi-channel frequency division module 203 are conventional circuit modules, wherein the multi-channel frequency division provides several working clocks, one of which is a 1HZ clock satisfying the 24-hour cycle timer, and there is also a global operating clock.

The chip is powered by the main power supply VCC and the backup battery power supply VCC1. VCC1 supplies power for the clock circuit, multi-channel frequency division module, 24-hour cycle counter, non-volatile memory and system reset circuit to ensure the power supply when the main power supply VCC of the chip is powered off. There is no handover work, no data loss and 24-hour cycle counters can operate normally.

The non-volatile memory 110 ensures that the contents thereof will not be lost when the power is turned off. The content includes: two-way sampling cycle time constant, sampling quantization standard table (the required number of digits can be determined according to the accuracy, if 8 bits are binary values between 0-255), the starting time value of timing work (3 bytes of data), Timing work end time value (3 bytes of data), working parameters during the working period of timing work (for example, corresponding to mains voltage or ambient brightness index), safe working temperature upper limit, and limit temperature value. These values can be changed via the communication interface, allowing remote control. Some constants can be determined as fixed values according to user needs. The volatile memory plus the non-volatile memory have a total of 16-bit addressing space, and the initial value of the 24-hour timer (for time calibration, 3 bytes) can be stored in the volatile memory. Its internal connection relationship and working principle are:

Capacitors C4, C5 and crystal oscillator XTAL form an external oscillator source, which is connected to the clock generation module 202 through pins XTAL0 and XTAL1, the clock generation module 202 is connected to the multi-channel frequency divider 203, and the timing clock CLK1 generated by the multi-channel frequency divider 203 is connected to To the 24-hour cycle counter 204, the 24-hour cycle counter 204 generates a 16-bit output connected to the time comparator 208, the non-volatile memory 110, connected to the time comparator (208) to give the comparison value of the time, and the time setting from the communication interface The control signal is connected to the 24-hour cycle counter 204, and the time calibration value setting from the communication interface is connected to the volatile memory 107. The power-off signal can be taken from the main power supply VCC and connected to the power-off restart timer 207, and the output restart signal generated by the power-off restart timer 207 is connected to an input end of a two-OR gate 209, and the other input end is connected to the reset signal Reset , the output generated by the two OR gate 209 is connected with the input terminal of the volatile memory bank 206, with the input terminal of the time comparator, and also connected with other functional modules powered by VCC to ensure reliable reset. The 24-hour cycle counter 204 is always in work, but it will start counting from 0 again after the 24-hour count is full, and the count value produced is always consistent with the regular work start time value and the regular work end time stored in the nonvolatile memory 110 Value is compared in time comparator 208, will produce a timing start point to signal output when counting value and timing work start time value are equal, and turn into and do comparison operation with timing work end time value. When the count is equal to the timing end time value, a timing end point arrival signal output will be generated, and it will be converted into a comparison operation with the timing work starting point time value. These two signal lines will be connected to the PWM module 109 to trigger the PWM module to recalculate the PWM.

See Figure 5, Figure 5 is a communication interface and chip address module diagram, the four address programming pins A0~A3 are respectively connected to the chip address module 301, the chip address module can determine the chip address according to the four programming pins, four pins By connecting the power supply VCC and grounding, 15 different addresses except 0 can be formed, and a maximum of 15 chips can be used to form a host chip structure network. The chip address module 301 is connected to the volatile memory 107. Once the chip is powered on, it will start writing Into the line, the chip address module 301 will write the address value of the chip to the corresponding address in the volatile memory 107, the communication interface 303 is connected with the volatile memory 107, and the two external pins of the communication port are RX and TX, which can be connected externally The host is internally connected to the communication interface 303 in the chip, and the communication interface 303 is connected to the non-volatile memory 110 . Its working principle is as follows: the external connection lines of the four address programming pins A0-A3 are written into the volatile memory 107 through the chip address module 301 through the combination of the power supply VCC and the ground connection. The working process of the communication is: 1) first the remote host sends a start signal; 2) then the remote host sends a read signal to read the 8-bit chip address value address in a certain address in the volatile memory 107, and then proceed through the communication interface 303 After parallel-to-serial conversion, return to the host for comparison operation. The host has preset address parameters. If they are not equal after comparison, exit the communication, otherwise proceed to the next step. 3) When the comparison results are equal, there are three possible control operations: reading or writing of the non-volatile memory, and time correction. During any control operation, the control signal is maintained until the next control signal arrives. If it is the operation of multiple pieces of data on the non-volatile memory, it is necessary to determine a number of addresses to do the cycle operation (not necessarily to obtain the address continuously), if it is the operation of correcting the time, send the calibration value to the volatile memory, 24-hour cycle counter 204 will be triggered to achieve the calibration time. After the communication is completed, the control signal is released from hold. The communication interface performs data serial-to-parallel data conversion and reverse parallel-to-serial conversion and data transmission, controls the flow and retention of signals, and controls the direction of data communication.

Referring to FIG. 6, FIG. 6 is a schematic diagram of the PWM module . The digital logic circuit 116 is connected to the nonvolatile memory 110 through the readout line, the address line and the data line; the digital logic circuit 116 changes the signal line, the address line, and the data line through the PWM cycle. And readout line is connected with PWM period counter 113; Digital logic circuit 116 is connected with PWM pulse width counter 112 through PWM pulse width change signal line, address line, data line and readout line; Digital logic circuit 116 is connected through data line, address line and the writing line is connected with the volatile memory 107; the PWM period counter 113 is connected with the volatile memory 10) through the readout line, the address line and the data line; the PWM pulse width counter 112 is connected with the volatile memory through the readout line, the address line and the data line The PWM cycle counter 113 is connected with the PWM pulse width counter 112 by the count overflow signal line of the readout line, the address line, the data line and (113); the count overflow signal line of the PWM pulse width counter 112 is connected with the PWM generator 114 connected; PWM generator 114 generates PWM signal output.

5 control signals: environmental brightness change signal, temperature abnormal signal, timing start point arrival signal, timing end point arrival signal, LED parallel branch abnormal signal are sent to the digital logic circuit 116 respectively, and the digital logic circuit (116) executes the following steps: PWM reset The priority order of the calculation request is as follows according to the work safety level: 1. LED parallel branch abnormal signal, 2. Temperature abnormal signal, 3. Timing start point arrival signal, timing end point arrival signal, 4. Environmental brightness change signal. The algorithm of PWM calculation is described as follows: at the beginning, see which control signal arrives, if there is no control signal, do PWM calculation according to the ambient brightness data, if the abnormal temperature signal arrives, but the temperature is at the upper limit of safe working temperature, the limit temperature value Between, the reverse slope method is used as the calculation basis for the duty cycle. When the limit temperature is reached, the PWM duty cycle is the minimum and there is no output. When the abnormal signal of the LED parallel branch arrives, the duty cycle is calculated according to the number of open circuits of the LED parallel branch. If the signal arrives from the timing starting point, read the required dimming working parameters (such as the set mains voltage or brightness index), and calculate the duty cycle. If the signal arrives at the end of the timing, restore the normal dimming parameter value and calculate the duty cycle, so the calculation still adapts to the change of ambient light, which is to change the duty cycle again on the basis of the duty cycle of ambient light control. The essence of its PWM calculation is to generate two counted values and store them in the volatile memory 107. As long as the counted value changes, it will trigger the corresponding two counters 112 and 113, which will change the counted value. The corresponding count value is read out from the memory 107 and counted again. The generation of PWM is determined by two parameters, i.e. pulse period and pulse width, which can be obtained by two counters PWM period counter 113 and PWM pulse width counter 112. When 112 starts counting, the PWM pulse begins to generate until the counting is completed, and then Generate the falling edge of the pulse and wait for the end of 113 counting. When 113 counts overflow, trigger 112 to start counting again, and 113 also counts again to enter the cycle of the next cycle.

If the number of LED parallel branches is less than the number set by the chip, the extra pins should be connected to the positive power supply VCC. For the programming of the chip address, a 4-way SPDT jumper switch or DIP switch should be installed on the PCB, and the positive power or ground should be connected according to different jumpers to realize the address programming requirements. After the address of the chip is determined, the chip can be controlled through the network, communicate through the communication interface of the communication interface, set the timing time and timing work parameter values, and the LED can emit different brightness under the same ambient brightness. It can be implemented by network or by a single chip, and when implemented by a single chip, the setting of the chip address can be ignored.

Claims (10)

1. A LED power supply control chip is characterized in that it comprises: a signal measurement module, a sampling control module, a communication interface, a sample comparator, a clock and a frequency division module, a chip address module, a volatile memory, a nonvolatile memory, 24 Hour cycle counter, LED parallel branch open circuit number adder, time comparator, PWM module, signal measurement module and sampling control module are connected to establish a sampling channel and obtain sampling data; the sampling control module is respectively connected to the sample comparator, volatile The memory is connected to the PWM module, the sample comparator is connected to the non-volatile memory, and the sample data from the non-volatile memory is compared and the result is stored in the volatile memory, the volatile memory is connected to the PWM module, and the sampling control module is connected to the The ambient brightness value is compared with the current value stored in the volatile memory. If the ambient brightness value changes, the sampling control module will send an ambient brightness change signal to the PWM module; the sampling control module will compare the measured temperature value with the non-volatile If it is not within the normal temperature range, the sampling control module sends a temperature abnormal signal to the PWM module, the non-volatile memory is connected to the PWM module, and the PWM module extracts the parameters stored in the non-volatile memory, 24 The hour cycle counter is connected to the time comparator, and the time comparator is connected to the non-volatile memory and the PWM module. The time comparator is used to compare with the timing value from the non-volatile memory. , the time comparator will start the connection with the PWM module to start the PWM calculation based on this condition; the clock frequency division module is connected with the 24-hour cycle counter, the chip address module is connected with the volatile memory, and the chip address is stored in it, and the communication interface It is connected with volatile memory to retrieve the chip address to the remote host; the communication interface is connected with the 24-hour cycle counter to start the calibration time, and the communication interface is connected with non-volatile memory to set, modify or receive parameters, LED The open circuit number adder of the parallel branch is connected with the PWM module and the volatile memory, and performs carry addition operation on the parallel open circuit status of all LED branches. If an abnormality occurs in the LED parallel branch, the result of the carry addition operation is sent to the volatile memory. And transmit the LED parallel branch abnormal signal to the PWM module. 2. A LED power supply control chip as claimed in claim 1, characterized in that: said signal measurement module includes 3 resistors built into the chip, one is a standard precision resistor RS, one is a thermistor RT, and one is a conventional Resistors R, RS and R are connected to the sampling control module (106) through the on-off control module (105), and the thermistor RT is connected to the strobe switch (104) through the on-off control module (105) and then connected to the sampling control module (105). The modules (106) are connected, and the other ends of the three resistors are connected together, and connected to an off-chip capacitor C1, and the other end of C1 is grounded. 3. An LED power supply control chip according to claim 2, characterized in that: the photoresistor RL is placed outside the chip, connected to the gate switch (104) inside the chip, and then passed through the on-off control module (105) Connect with sampling control module (106). 4. An LED power supply control chip according to claim 2, characterized in that: the ambient light voltage signal V(t) is connected to the resistor R1 through the strobe switch (101), and the resistor R1 is connected to the charging capacitor C2 and the comparator ( 102), the inverting terminal of the comparator (103) is connected, the inverting terminal of the comparator (103) is grounded to form a zero comparator, the reference voltage Vf is connected to the non-inverting terminal of the comparator (102), and the comparator The output of (102) is connected to the pin B0 of the chip, and this pin is connected to the sampling control module (106), and the output of the comparator (103) is connected to the pin B1 of the chip, and this pin is connected to the sampling control module (106 ), the strobe signal line of the strobe switch (101) is connected to the sampling control module (106) through the chip pin B2. 5. A LED power supply control chip as claimed in claim 1 or 2, characterized in that it is also provided with a backup battery charging module, and the backup battery charging module is connected with the clock frequency division module to obtain a correct clock. 6. A LED power supply control chip according to claim 5, characterized in that the backup battery charging module: the main power supply VCC is connected to the non-inverting terminal of the comparator (201) through a resistor R2, and the non-inverting terminal of the comparator (201) The terminal is grounded through R3, the output terminal of the comparator (201) is connected to the base of the transistor Q through the resistor R4, the emitter of Q charges the battery BT through the diode D2, and the collector of Q is connected to the main power supply VCC through the diode D1, Q The emitter of Q is connected to the ground through the capacitor C3, the emitter of Q is connected to the resistor R6, and then connected to the ground through R7, the base of Q is connected to the ground through the resistor R5, the emitter of Q is connected to the resistor R6, and then connected to the comparison The inverting terminal of the device (201) obtains the feedback signal. 7. A LED power supply control chip as claimed in claim 1 or 2, characterized in that the chip address module has 4 address programming pins A0-A3, and the 4 address programming pins A0-A3 are respectively connected to the chip The address module (301), the chip address module can determine the chip address according to the 4 programming pins, and the 4 address programming pins A0~A3 can form 15 different addresses except the 0 address through the combination of the power supply VCC and the ground. It can realize a host chip structure network composed of up to 15 chips. 8. An LED power supply control chip as claimed in claim 1 or 2, characterized in that: the chip (100) has 24 pins: main power pin VCC, backup battery power pin VCC1, ground wire GND, two Two clock pins XTAL0 and XTAL1, two communication interface pins RX and TX, which can be connected to the host externally and internally connected to the communication interface (303) in the chip, 4 address programming pins A0~A3, and two resistors for comparison sampling Pins X0 and X1, 3 RC charge and discharge sampling pins B0~B2, 6 LED parallel branch circuit break feedback signal pins IO-0~IO-5. 9. A LED power supply control chip as claimed in claim 8, characterized in that: said LED parallel branch open circuit number adder is connected to the voltage sampling of LED parallel branch through chip pins IO-0-IO-5 Level signal, judge the sum of LED parallel branch open circuit. 10. A kind of LED power supply control chip as claimed in claim 1 or 2, is characterized in that: the digital logic circuit (116) of described PWM module communicates with nonvolatile memory (110) through readout line, address line and data line ) is connected; the digital logic circuit (116) is connected to the PWM cycle counter (113) through the PWM cycle change signal line, address line, data line and readout line, and the digital logic circuit (116) changes the signal line and address line through the PWM pulse width , the data line and the readout line are connected with the PWM pulse width counter (112); the digital logic circuit (116) is connected with the volatile memory (107) through the data line, the address line and the write line; The outgoing line, the address line and the data line are connected with the volatile memory (107); the PWM pulse width counter (112) is connected with the volatile memory (107) through the readout line, the address line and the data line; the PWM cycle counter (113) is passed through The count overflow signal line of readout line, address line, data line and (113) is connected with PWM pulse width counter (112); the count overflow signal line connected with PWM pulse width counter (112) is connected with PWM generator (114); (114) Generate PWM signal output.

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