A low-power charging control method with adaptive standby mode

Abstract

The application discloses a low-power charging control method of self-adaptive standby mode, relates to the technical field of low-power charging control, and comprises the following steps: S1, a detection circuit integrated in an ASIC of a chip is used to collect battery charging voltage, current and temperature parameters in real time, and the detection circuit controls the charging voltage detection error precision to be within 1% through a built-in calibration module; S2, an input power supply is processed through a 4.5-6V wide voltage adaptation circuit, and a trickle current, a constant current, a constant voltage and a full-charge-off stage are determined in combination with preset threshold values and temperature; and S3, a control module adjusts a module state through a power management circuit, cuts off the power supply of unnecessary modules to make the static current be less than or equal to 5 mu A during standby, and triggers a protection standby mode according to an abnormal signal. Through a hardware interrupt circuit, the application realizes low-power control of the self-adaptive standby mode, solves the problem that the power consumption of a charging circuit is high during standby, reduces the standby power consumption of a chip, and enables the charging to be quickly restored in the standby state.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of low-power charging control, in particular to a low-power charging control method with adaptive standby mode. BACKGROUND

[0002] With the popularity of portable electronic devices and the development of battery technology, higher requirements are put forward for low-power, high-integration, safety and adaptability of charging control circuit. The traditional charging control scheme has the following problems: first, it relies on external voltage comparators, protection chips and other discrete components, resulting in high material cost and complex PCB layout; second, the static current is large in standby mode, and the power consumption control is insufficient; third, the adaptation ability to wide range input voltage is limited, and the charging parameter detection precision is difficult to meet the high-precision battery management demand; fourth, the protection mechanism response speed is slow in abnormal working condition, which is easy to cause safety hazards.

[0003] Patent CN109713751B discloses a battery low-power standby control circuit and method, which realizes switching between low-power standby mode and normal working mode at any time, and automatically exits low-power standby mode during charging. In low-power standby mode, standby power consumption is effectively reduced, battery endurance time is effectively prolonged, and the purpose of low-power standby is finally achieved. Touch key can be used as trigger signal for entering and exiting low-power standby mode, and also can realize normal touch key function.

[0004] The above-mentioned patent realizes switching between low-power standby mode and normal working mode, effectively reduces standby power consumption, prolongs battery endurance time, and gives touch key double function; however, it does not study how to dynamically adjust standby strategy in combination with real-time charging parameters during charging process, accurately match low-power demand in charging stage, and cope with adaptive protection mechanism for abnormal conditions such as short circuit, overvoltage and overheating during charging process.

[0005] Therefore, the present application provides a low-power charging control method with adaptive standby mode, which realizes multiple real-time protection mechanisms and uses hardware interrupt wake-up technology to achieve ultra-low power control. SUMMARY

[0006] The present application aims to provide a low-power charging control method with adaptive standby mode, which solves the technical problems of traditional charging control scheme relying on external voltage comparators, protection chips and other discrete components, resulting in high material cost, complex PCB layout, large static current in standby mode and insufficient power consumption control.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a low-power charging control method with adaptive standby mode, comprising the following steps:

[0008] S1, real-time collection of battery charging voltage, current and temperature parameters by detection circuit integrated in ASIC in chip, the detection circuit controls the charging voltage detection error precision within 1% through the built-in calibration module;

[0009] S2, processing input power supply through 4.5-6V wide voltage adaptation circuit, combining preset threshold and temperature to determine trickle, constant current, constant voltage and full charge off stage;

[0010] S3, the control module adjusts the module state through the power management circuit, cuts off the power supply of unnecessary modules when on standby to make the static current ≤5μA, and triggers the protection standby mode according to the abnormal signal;

[0011] S4, cut off the output in standby, when the hardware interrupt circuit in the chip detects that the charging current is lower than 1% of the rated charging current of the battery, the hardware interrupt circuit wakes up the chip to resume charging within 100μs;

[0012] The detection circuit is integrated in the ASIC, the voltage and temperature detection input end is connected to the positive and negative poles of the battery through the chip pin and internal wire, the current detection input end is connected to the sampling resistor in series in the charging loop, and the output end of the detection circuit is connected to the data input interface of the control module through the internal bus;

[0013] The input and output ends of the built-in calibration module are connected with the detection circuit and the control module through the internal bus;

[0014] The input end of the wide voltage adaptation circuit is connected to the external input power supply through the chip power supply pin, and the output end provides working voltage for each module in the chip;

[0015] The control module exchanges data and transmits control signals with the detection circuit, the built-in calibration module, the power management circuit and the hardware interrupt circuit through the internal bus;

[0016] The power management circuit is controlled by the control module, and the output is connected to the necessary modules and unnecessary modules in the ASIC chip through the internal power network, for cutting off the power supply of unnecessary modules in standby mode;

[0017] The signal input end of the hardware interrupt circuit is connected to the voltage comparator output end or the dedicated wake-up signal line in the detection circuit, and the output end is connected to the interrupt request pin of the control module.

[0018] Preferably, the ASIC integrates the voltage comparator, the analog-to-digital converter and the control logic unit required for charging control on the same chip substrate through layout and wiring, the input and output pins are distributed around the chip, and the voltage comparator, the analog-to-digital converter and the control logic unit are connected through metal wires;

[0019] The input pin of the voltage comparator is directly connected to the external detection circuit, and the output pin is connected to the control module through an internal lead, which connects the input power supply to the power supply pin of the chip, connects the positive and negative electrodes of the battery to the charging input pin of the chip, connects the LED to the status pin and connects the resistance in series to the ground.

[0020] Preferably, the wide voltage adaptation circuit realizes power supply processing through a multi-stage voltage stabilization circuit in the chip, which includes a front-end anti-reverse connection diode circuit, an LC filter circuit and a DC-DC voltage stabilization circuit. The anode of the anti-reverse connection diode circuit is connected to the positive pin of the input power socket through a PCB lead, and the cathode is connected to one end of the inductor of the LC filter circuit through a lead. The other end of the LC filter circuit is connected to one end of the ceramic capacitor and the input pin of the DC-DC voltage stabilization circuit through a lead, and the other end of the ceramic capacitor is connected to the ground through a lead.

[0021] The DC-DC voltage stabilization circuit adopts a synchronous buck topology, the gate of the internal switch tube is connected to the output pin of the PWM control chip through a lead, the power supply pin of the PWM control chip is connected to the cathode of the anti-reverse connection diode through a lead, the feedback pin of the PWM control chip is connected to the voltage dividing circuit of the charging module power input pin through a lead, and the PWM mode dynamically adjusts the duty cycle according to the input voltage and load changes.

[0022] Preferably, in the charging voltage detection, the analog input pin of the 24-bit sigma-delta analog-to-digital converter in the ASIC is connected to the output end of the programmable gain amplifier through a lead, the input end of the programmable gain amplifier is connected to the battery voltage detection circuit through a lead, and the gain control pin of the programmable gain amplifier is connected to the GPIO pin of the control module through a lead. The control module outputs different level combinations to the GPIO pin according to the battery voltage range, and controls the amplification multiple of the programmable gain amplifier through the internal decoding circuit.

[0023] The reference voltage pin of the analog-to-digital converter is connected to the output end of the bandgap reference source in the chip through a lead, and the digital output pin of the analog-to-digital converter is connected to the data input interface of the control module through an internal bus. Combined with the calibration data of the bandgap reference source and the analog-to-digital converter at different temperatures before leaving the factory, the detection result is adjusted through a digital calibration algorithm.

[0024] Preferably, in the full-charge shutdown phase, the PWM output pin of the control module is connected to the input end of the drive circuit through a lead, and the output end of the drive circuit is connected to the gate of the power MOSFET of the charging output loop through a lead. The source of the MOSFET is connected to the positive electrode of the charging power supply through a lead, and the drain is connected to the positive electrode of the battery through a lead.

[0025] In the late constant-voltage charging stage, the control module continuously reads the current data output by the analog-to-digital converter through the internal bus, and when the current drops to less than 1% of the rated charging current of the battery and lasts for 10 minutes, the control module sends a low-level signal to the driving circuit through the PWM output pin, the driving circuit outputs a low level, and the MOSFET is cut off; the control module outputs a signal to the LED driving circuit through another GPIO pin to control the LED to be extinguished and slowly flashed.

[0026] Preferably, the source of the PMOS switch of the power management circuit is connected to the chip power input pin through a wire, and the drain is connected to the power input pins of the unnecessary modules through wires; in the standby mode, the control module sends a low-level signal to the PMOS gate through the internal driving circuit, and the power supply pin of the analog-to-digital converter is connected to a turn-off power switch through a wire;

[0027] The power supply pin of the voltage comparator is connected to the low-power LDO stabilizer output end in the chip through a wire, the LDO input is connected to the chip power supply, and the output end is connected to the power supply pin of the voltage comparator and the control module circuit through a wire, and the logic unit in the control module enters a sleep state when the control module is in the standby mode, and the power supply pins of the processing unit and the register are connected to the LDO stabilizer output end through independent low-power lines.

[0028] Preferably, the positive and negative input ends of the current detection amplifier in the ASIC are connected to the two ends of the sampling resistor through wires, the sampling resistor is connected in series in the charging loop, and the output end of the current detection amplifier is connected to the external interrupt pin of the control module through a wire;

[0029] When the voltage difference between the two ends of the sampling resistor exceeds the short-circuit threshold, the current detection amplifier outputs a high-level signal to the interrupt pin of the control module, the control module sends a control signal to the driving circuit through the internal bus within 20μs to close the charging output driving circuit, and the control module starts an internal 1s timer. If the voltage difference of the sampling resistor is higher than the threshold within 1s, the control module cuts off the power supply of the unnecessary circuits through the power management circuit.

[0030] Preferably, the detection lines of the negative electrode and the positive electrode of the battery are connected to the input end of the undervoltage protection detection circuit through wires, and when the battery voltage is lower than the undervoltage threshold, the undervoltage protection detection circuit sends a low-level signal to the interrupt pin of the control module through a wire, the control module calls the trickle charging program through the internal bus, the PWM output pin of the trickle charging program sends a duty cycle signal to the driving circuit to perform trickle charging at a current of 5% of the rated charging current of the battery, and if the battery voltage continues to be lower than the undervoltage threshold for 10 minutes, the control module determines that the battery is abnormal and cuts off the power supply of the trickle charging circuit through the power management circuit. When the voltage monitoring circuit supplied by the independent low-power power supply detects that the battery voltage recovers to above the undervoltage threshold, the control module wakes up the battery through the hardware interrupt circuit.

[0031] Preferably, the output end of the chip internal temperature sensor is connected to the ADC input pin of the control module through a wire, the control pin of the clock generator is connected to the control module, the input end of the heat dissipation control circuit is connected to the control module, and the output end of the heat dissipation control circuit is connected to the chip heat dissipation pin driving circuit through a wire;

[0032] When the control module reads a temperature value exceeding a preset threshold value, a signal is sent to the power management circuit and the heat dissipation control circuit through an internal bus, and the power management circuit reduces the module working frequency by adjusting the output frequency of the clock generator.

[0033] Preferably, the control module interrupt pin is connected to the output end of the VCC overvoltage protection detection circuit, and the input end of the VCC overvoltage protection detection circuit is connected to the chip VCC power pin through a wire. When it is detected that the VCC voltage exceeds a preset overvoltage value, the detection circuit sends a high-level signal to the control module interrupt pin through a wire, the control module cuts off the MOSFET switch of the charging input loop through the driving circuit, and the control module outputs an alarm signal through another GPIO pin. When the detection circuit continuously monitors and sends a low-level signal to the control module interrupt pin to show that the VCC voltage has returned to the normal range, the control module timer delays for 500 ms, and the control module re-detects the input voltage and restores the charging through the interrupt wake-up.

[0034] Compared with the prior art, the present application has the following beneficial effects:

[0035] 1. The present application realizes low-power control of adaptive standby mode through a hardware interrupt circuit, solves the problem of high power consumption of the charging circuit in standby mode, reduces the standby power consumption of the chip, and can quickly restore charging in the standby state.

[0036] 2. The present application integrates the voltage comparator, the analog-to-digital converter and the control logic unit on the same chip substrate through ASIC, realizes multi-functional high integration, solves the problems of high material cost and large PCB layout area of traditional charging circuits, and simplifies the circuit design.

[0037] 3. The present application realizes wide voltage adaptation and high-precision charging parameter detection through a wide voltage adaptation circuit, solves the problems of narrow input voltage range and large charging voltage detection error, and improves the compatibility of the charging circuit to different input power supplies.

[0038] 4. The present application realizes real-time monitoring and rapid protection of abnormal conditions during charging through an under-voltage protection detection circuit, solves the problem of safety hazards caused by abnormal conditions during charging, and improves the reliability and safety of the charging system. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1Fig. 1 is a schematic diagram of an ASIC chip architecture according to the present application;

[0040] Figure 2 Fig. 2 is a schematic diagram of a chip peripheral connection circuit according to the present application;

[0041] Figure 3 Fig. 3 is a schematic diagram of a VCC overvoltage protection process according to the present application;

[0042] Figure 4 Fig. 4 is a schematic diagram of a wide voltage adaptation circuit structure according to the present application. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0044] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 An embodiment provided by the present application is a low-power-consumption charging control method in an adaptive standby mode, comprising the following steps:

[0045] S1, real-time collection of battery charging voltage, current and temperature parameters is performed by using a detection circuit integrated in an ASIC in a chip, and the detection circuit controls the charging voltage detection error precision to be within 1% through a built-in calibration module;

[0046] S2, input power is processed by a 4.5-6V wide voltage adaptation circuit, and a trickle current, a constant current, a constant voltage and a full-charge-off stage are determined in combination with a preset threshold and temperature;

[0047] S3, a module state is adjusted by a power management circuit, and power supply to unnecessary modules is cut off in standby mode to make a static current ≤5μA, and a protection standby mode is triggered according to an abnormal signal;

[0048] S4, output is cut off in standby mode, and when a charging current detected by a hardware interrupt circuit in the chip is lower than 1% of a rated charging current of a battery, a wakeup condition is met, and the hardware interrupt circuit wakes up the chip to resume charging within no more than 100μs;

[0049] The ASIC integrates the voltage comparator, the analog-to-digital converter and the control logic unit required for the charging control on the same chip substrate through layout and wiring, the input and output pins are distributed around the chip, and the voltage comparator, the analog-to-digital converter and the control logic unit are connected through metal wires; the input pin of the voltage comparator is directly connected to the external detection circuit, and the output pin is connected to the control module through the internal wire; the wire connects the input power supply to the chip power supply pin, the positive and negative electrodes of the battery to the chip charging input pin, the LED to the state pin and the series resistance to the ground;

[0050] Further, taking the SG802 series air pressure sensor as an example, in the system peripheral application circuit, the power input pin of the ASIC chip is connected to the input filter capacitor through a wire, one end of which is connected to the pin and the other end is grounded; the charging output pin is connected to one end of the energy storage inductor through a wire, the other end of the energy storage inductor is connected to the positive electrode of the battery through a wire, and the negative electrode of the battery is grounded; the status indication LED is connected to the chip state pin through a wire and grounded after being connected in series with a current limiting resistor. Due to the high integration of the ASIC chip, no external voltage comparator, protection chip and other components are required, only a small number of peripheral components are required, and the material cost and PCB layout area are reduced;

[0051] First, the positive and negative electrodes of the battery are connected to the "+" and "-" pins of the chip respectively, and the detection circuit designed by the ASIC in the chip is used; the detection circuit includes a 24-bit sigma-delta analog-to-digital converter and a programmable gain amplifier (PGA); the PGA automatically adjusts the amplification multiple according to the initial voltage of the battery, and the battery voltage and current signals are input into the analog-to-digital converter after being filtered to convert them into digital signals for analysis by the control module.

[0052] Then, the control module compares the collected voltage and current with the preset threshold based on the analog signal processing and digital logic judgment principles inside the chip; the regulated battery voltage signal is input into one input terminal of the comparator, and the constant voltage charging threshold reference voltage is input into the inverting terminal; if the battery voltage signal is higher than the reference voltage, the comparator outputs a high level, and the control module determines that it enters the constant voltage charging stage; the regulated current conversion voltage signal is input into the non-inverting terminal of another comparator, and the constant current charging threshold reference voltage is input into the inverting terminal; if the current signal is higher than the reference voltage, the comparator outputs a high level, the charging current is maintained at 1C of the rated charging current of the battery, and the voltage gradually rises, and the control module determines that it enters the constant current charging stage; if the current signal is lower than the reference voltage and lower than the trickle threshold \(0.1V\), it is determined to be trickle charging; when the external device temporarily stops the power supply request, i.e. needs to enter the standby mode, the control module sends a command to the power management circuit, cuts off the power supply of the charging pulse generation module, the voltage regulation auxiliary module and other unnecessary modules through the PMOS switch tube, only retains the basic power supply of the detection circuit and the control module, and the static current of the chip is reduced to ≤5μA.

[0053] Finally, when the detection circuit detects that the battery voltage is lower than the wake-up threshold through the hardware interrupt circuit, the voltage comparator output end level jumps, an interrupt trigger signal is generated, the interrupt trigger signal is connected to the hardware interrupt pin of the chip through PCB wiring, and is input to the interrupt controller in the chip. The interrupt controller detects the level change of the pin and identifies it as a valid interrupt request. The interrupt controller sends a wake-up instruction to the control module through the internal bus. After the control module receives the wake-up instruction, the low-power operation in the standby mode is stopped, the power supply to each module is restored, then the control module reads the interrupt flag register to confirm that it is a voltage wake-up event, calls the initialization program, restarts the analog-to-digital converter and the signal conditioning circuit, initializes the register state, and starts the normal charging process judgment to restore the constant current charging mode.

[0054] Please refer to Figure 1 、 Figure 3 and Figure 4 , the present application provides an embodiment: a low-power charging control method in adaptive standby mode, the wide voltage adaptation circuit realizes power supply processing through the multi-stage voltage stabilizing circuit in the chip, the multi-stage voltage stabilizing circuit includes a front-end anti-reverse connection diode circuit, an LC filter circuit and a DC-DC voltage stabilizing circuit, the anode of the anti-reverse connection diode circuit is connected to the positive pole pin of the input power socket through the PCB wire, and the cathode is connected to one end of the inductor of the LC filter circuit through the wire; the other end of the LC filter circuit is connected to one end of the ceramic capacitor and the input pin of the DC-DC voltage stabilizing circuit through the wire, and the other end of the ceramic capacitor is grounded through the wire; the DC-DC voltage stabilizing circuit adopts a synchronous step-down topology, the gate of the internal switch tube is connected to the output pin of the PWM control chip through the wire, the power supply pin of the PWM control chip is connected to the cathode of the anti-reverse connection diode through the wire, the feedback pin of the PWM control chip is connected to the voltage division circuit of the charging module power input pin through the wire, and the PWM mode dynamically adjusts the duty cycle according to the input voltage and the load change;

[0055] In the charging voltage detection, the analog input pin of the 24-bit sigma-delta analog-to-digital converter in the ASIC is connected to the output end of the programmable gain amplifier through the wire, the input end of the programmable gain amplifier is connected to the battery voltage detection circuit through the wire, the gain control pin of the programmable gain amplifier is connected to the GPIO pin of the control module through the wire, the control module outputs different level combinations to the GPIO pin according to the battery voltage range, and the amplification multiple of the programmable gain amplifier is controlled through the internal decoding circuit; the reference voltage pin of the analog-to-digital converter is connected to the output end of the bandgap reference source in the chip through the wire, and the digital output pin of the analog-to-digital converter is connected to the data input interface of the control module through the internal bus; combined with the calibration data of the bandgap reference source and the analog-to-digital converter at different temperatures before leaving the factory, the detection result is adjusted through the digital calibration algorithm;

[0056] Further, first in the charging circuit in series sampling resistance, sampling resistance both ends connected to the ASIC current detection amplifier positive and negative input terminals; sampling resistance voltage difference detection, calibration module for current detection amplifier calibration, to ensure the accuracy of short-circuit threshold detection; when the charging circuit accidental short-circuit, sampling resistance both ends voltage difference instantaneously exceeds the short-circuit threshold.

[0057] Then, the current detection amplifier outputs a high level signal to the external interrupt pin of the control module, and the control module sends a control signal to the drive circuit through the internal bus within 20 μs. The drive circuit is an intermediate circuit connected between the control module and the power MOSFET, which converts the signal of the control module into a level signal suitable for driving the MOSFET. The drive circuit outputs a low level signal to the gate of the power MOSFET in the charging output circuit. The conduction of the power MOSFET depends on the voltage difference between the gate and the source. When the gate receives a low level signal, Vgs is lower than the conduction threshold of the MOSFET, and the conduction channel in the MOSFET cannot be formed, so it enters the cutoff state. Therefore, the charging output circuit is disconnected, and the current cannot pass through, realizing the cut-off of the charging output.

[0058] Finally, the control module starts the internal 1 s timer. If the voltage difference of the sampling resistance is still higher than the threshold within 1 s, the control module further cuts off the power supply of the unnecessary circuit through the power management circuit, and enters the deep sleep mode. If the voltage difference of the sampling resistance is lower than the threshold, i.e. the short circuit is eliminated, the detection circuit triggers a hardware interrupt to wake up the chip, and the control module re-detects the state of the charging circuit. After normal, it restores the charging preparation process.

[0059] Please refer to Figure 1 , Figure 2 and Figure 3 , the present application provides an embodiment: a low-power charging control method in adaptive standby mode, in the full charge off stage, the PWM output pin of the control module is connected to the input end of the drive circuit through a wire, and the output end of the drive circuit is connected to the gate of the power MOSFET in the charging output circuit through a wire; the source of the MOSFET is connected to the positive electrode of the charging power supply through a wire, and the drain is connected to the positive electrode of the battery through a wire; in the late constant voltage charging stage, the control module continuously reads the current data output by the analog-to-digital converter through the internal bus. When the current drops to less than 1% of the rated charging current of the battery and lasts for 10 minutes, the control module sends a low level signal to the drive circuit through the PWM output pin, the drive circuit outputs a low level, and the MOSFET is cut off. The control module outputs a signal to the LED drive circuit through another GPIO pin to control the LED to be extinguished and slowly flashed.

[0060] The source of the PMOS switch of the power management circuit is connected to the chip power input pin through a wire, and the drain is connected to the power input pin of the unnecessary module through a wire; in the standby mode, the control module sends a low-level signal to the PMOS gate through the internal drive circuit, the power supply pin of the analog-to-digital converter is connected to a turn-off power switch through a wire; the power supply pin of the voltage comparator is connected to the low-power LDO stabilizer output end in the chip through a wire, the LDO input is connected to the chip power supply, and the output end is connected to the power supply pin of the voltage comparator and the control module circuit through a wire, and the logic unit in the control module enters the sleep state in the standby mode, and the power supply pins of the processing unit and the register are connected to the LDO stabilizer output end through independent low-power lines;

[0061] Further, first, the input end of the undervoltage protection detection circuit is connected to the battery positive and negative detection line; when it is detected that the battery voltage is lower than the undervoltage threshold, the detection circuit sends a low-level signal to the control module interrupt pin through a wire.

[0062] Then, the control module calls the trickle charging program through the internal bus, and the PWM output pin of the trickle charging program sends a specific duty cycle signal to the drive circuit to perform trickle charging at 5% of the rated charging current of the battery.

[0063] In the switching process of trickle charging, constant current charging and constant voltage charging, the state machine control module in the ASIC is connected to other modules through the internal bus. When switching from trickle charging to constant current charging, the control module gradually increases the duty cycle of the PWM output signal through the internal counter (the counter clock is provided by the chip clock source), and the charging current is gradually increased to the set constant current value through the drive circuit; when switching from constant current charging to constant voltage charging, the battery voltage reaches the set constant voltage value detected by the analog-to-digital converter and transmitted to the control module through the internal bus, the control module switches to voltage closed-loop control, adjusts the PWM duty cycle through the PID algorithm, dynamically adjusts the charging current, and the PID algorithm parameters are stored in the EEPROM in the chip. The EEPROM is connected to the control module through the I2C bus. During the whole switching process, the control module reads the temperature sensor data and voltage change rate in real time through the internal bus, and the voltage change rate is calculated by the adjacent two analog-to-digital conversion data; if the temperature suddenly changes more than 5℃ or the voltage change rate exceeds 0.1V / min, the control module enters the protection standby mode through the power management circuit.

[0064] Then, if the timer driven by the low-power clock source in the control module continues to monitor for 10 minutes and the battery voltage is still below the undervoltage threshold, the control module sends a shutdown instruction to the power management circuit through the internal bus based on the battery abnormality determination logic preset in the firmware program stored in the internal Flash memory. After receiving the instruction, the power management circuit controls the internal electronic switch to turn off the power supply line of the trickle charging circuit and stop the power supply to the trickle charging related modules. To maintain subsequent monitoring, only the voltage monitoring circuit powered by the independent low-power power supply is retained.

[0065] Finally, when the voltage monitoring circuit detects that the battery voltage has recovered to above the undervoltage threshold, the comparator output triggers an interrupt in the control module, and after the control module wakes up, it reinitializes the charging parameters and restores the normal charging process.

[0066] Please refer to Figure 1 , Figure 2 and Figure 4 , the present application provides an embodiment: a low-power charging control method in adaptive standby mode, the positive and negative input terminals of the current detection amplifier in the ASIC are connected to the two ends of the sampling resistor through wires, the sampling resistor is connected in series in the charging loop, and the output terminal of the current detection amplifier is connected to the external interrupt pin of the control module through wires; when the voltage difference between the two ends of the sampling resistor exceeds the short-circuit threshold, the current detection amplifier outputs a high-level signal to the interrupt pin of the control module, and the control module sends a control signal to the driving circuit through the internal bus within 20μs to turn off the charging output driving circuit. The control module starts an internal 1s timer, and if the voltage difference of the sampling resistor is higher than the threshold within 1s, the control module cuts off the power supply of unnecessary circuits through the power management circuit;

[0067] The detection lines of the negative and positive electrodes of the battery are connected to the input terminals of the undervoltage protection detection circuit through wires, and when the battery voltage is below the undervoltage threshold, the undervoltage protection detection circuit sends a low-level signal to the interrupt pin of the control module through wires, and the control module calls the trickle charging program through the internal bus. The PWM output pin of the trickle charging program sends a duty cycle signal to the driving circuit to perform trickle charging at 5% of the rated charging current of the battery. If the battery voltage remains below the undervoltage threshold for 10 minutes, the control module determines that the battery is abnormal and turns off the power supply of the trickle charging circuit through the power management circuit. When the voltage monitoring circuit powered by the independent low-power power supply detects that the battery voltage has recovered to above the undervoltage threshold, the control module wakes up the battery through the hardware interrupt circuit;

[0068] Further, first, the chip internal temperature sensor monitors the temperature in real time, the output end of the temperature sensor is connected to the ADC input pin of the control module, the temperature sensor converts the temperature signal into an analog voltage signal based on the temperature-voltage characteristic of the semiconductor PN junction, and outputs to the ADC input pin of the control module; the ADC converts the analog voltage into a digital signal through the successive approximation method so as to facilitate the control module to read; when the control module reads the temperature value exceeding the preset threshold, signals are sent to the power management circuit and the heat dissipation control circuit through the internal bus.

[0069] Then, since the chip power consumption is approximately proportional to the frequency, the frequency reduction can significantly reduce the dynamic power consumption and reduce the heat, so that the power management circuit adjusts the output frequency of the clock generator, and reduces the working frequency of all modules in the chip to 1 / 5 of the normal frequency; the heat dissipation control circuit increases the conduction capacity of the chip heat dissipation pin and the PCB heat dissipation layer through the driving of the transistor amplification circuit. The PCB heat dissipation layer is usually a large-area copper foil, and by increasing the conduction capacity, the heat in the chip is more quickly conducted to the copper foil, and then the heat is dissipated through air convection.

[0070] Then, if the temperature continues to rise above the critical value, the control module cuts off the power supply path of the charging output circuit through the switch tube in the power management circuit, and enters the overheat protection standby mode.

[0071] Finally, when the temperature sensor detects that the temperature drops to the safe range, the control module triggers an interrupt through the change of the temperature sensor output to wake up, reinitializes the heat dissipation control and charging parameters, and if the temperature is stable, the charging is resumed.

[0072] Please refer to Figure 1 , Figure 3 and Figure 4 , an embodiment provided by the application: a low-power consumption charging control method in adaptive standby mode, the output end of the chip internal temperature sensor is connected to the ADC input pin of the control module through a wire, the control pin of the clock generator is connected to the control module, the input end of the heat dissipation control circuit is connected to the control module, and the output end of the heat dissipation control circuit is connected to the chip heat dissipation pin driving circuit through a wire; when the control module reads the temperature value exceeding the preset threshold, signals are sent to the power management circuit and the heat dissipation control circuit through the internal bus, the power management circuit reduces the module working frequency by adjusting the output frequency of the clock generator;

[0073] The control module interrupt pin is connected to the output end of the VCC overvoltage protection detection circuit, and the input end of the VCC overvoltage protection detection circuit is connected to the chip VCC power supply pin through a wire. When it is detected that the VCC voltage exceeds the preset overvoltage value, the detection circuit sends a high-level signal to the control module interrupt pin through a wire, and the control module cuts off the MOSFET switch of the charging input loop through the driving circuit. The control module outputs an alarm signal through another GPIO pin; when the detection circuit continuously monitors and sends a low-level signal to the control module interrupt pin to show that the VCC voltage has returned to the normal range, the control module timer delays for 500 ms, and the control module re-detects the input voltage and restores the charging by being awakened through the interrupt.

[0074] Further, first, the input end of the VCC overvoltage protection detection circuit is connected to the chip VCC power supply pin, and the output end is connected to the control module interrupt pin; the hardware interrupt circuit of the chip uses an independent low-power clock source, and the output end of the independent low-power clock source is connected to the clock input pin of the interrupt circuit through a wire, thereby providing stable clock support for interrupt signal processing. The calibration module is composed of a high-precision reference voltage source, a calibration algorithm circuit and a calibration parameter register. The high-precision reference voltage source outputs a 2.5V signal to the input end of the detection circuit, the calibration algorithm circuit compares the output of the detection circuit with the reference signal, calculates the overvoltage detection threshold compensation coefficient, and stores it in the calibration parameter register; when it is detected that the VCC voltage exceeds the preset overvoltage value, the detection circuit sends a high-level signal to the control module interrupt pin.

[0075] Then, the control module cuts off the MOSFET switch of the charging input loop through the driving circuit, and outputs a high-level alarm signal through another GPIO pin. At this time, the system is in a protection state.

[0076] Next, when the VCC voltage returns to the normal range, the detection circuit sends a low-level signal to the control module interrupt pin. The interrupt trigger condition is configured by writing a register through the control module. For the charging access signal, a 20 ms debouncing filter is set through the digital filter in the interrupt circuit, and the clock of the digital filter is provided by a 32 kHz crystal oscillator.

[0077] Finally, after confirming that the voltage is stable, the control module is awakened through the interrupt. The control module first reads the interrupt flag register through the internal bus, judges the interrupt type, and then calls the corresponding initialization program to restore the charging process. The initialization program includes reading the charging parameters from the Flash memory in the chip. The data line, address line and control line of the Flash memory are connected to the control module. After reading the parameters, the input voltage is re-detected. If the voltage is normal, the control module initializes the charging input loop and restores the charging process; if it is still abnormal, the standby mode is maintained and continuous monitoring is performed.

[0078] Working principle: first, the use of ASIC integrated detection circuit in real-time acquisition of battery charging voltage, current and temperature parameters, through the built-in calibration module to ensure that the charging voltage detection error accuracy within 1%; wide voltage adaptation circuit input power, combined with the preset threshold and temperature to determine the trickle, constant current, constant voltage and full charge off and other charging phase.

[0079] Then, the control module according to the charging phase and abnormal signal, through the power management circuit adjustment module state; normal charging dynamic switching mode, standby when cutting off unnecessary module power supply, so that the static current is less than or equal to 5 mu A; in the presence of abnormal trigger protection standby mode, further cut off the power supply of unnecessary circuit, reduce power consumption.

[0080] Finally, in standby or protection mode, the hardware interrupt circuit continues to monitor the specific signal; when the wake-up condition is met, the hardware interrupt circuit wakes up the chip in a short time, and the control module is woken up, the interrupt flag register is read to judge the interrupt type, the charging parameters are read from the flash memory in the chip, the related modules are initialized, and the normal charging process or the corresponding processing logic is entered.

[0081] For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A low-power charging control method with adaptive standby mode, characterized in that: The method comprises the following steps: S1, real-time collection of battery charging voltage, current and temperature parameters by using detection circuit integrated in ASIC in the chip, the detection circuit controls the charging voltage detection error precision within 1% through the built-in calibration module; S2, processing of input power supply by 4.5-6V wide voltage adaptation circuit, combination of preset threshold and temperature to determine trickle, constant current, constant voltage and full charge off stage; S3, module state adjustment of control module through power management circuit, cut-off of unnecessary module power supply in standby mode to make static current ≤5μA, triggering of protection standby mode according to abnormal signal; S4, cut-off of output in standby mode, detection of charging current lower than 1% of battery rated charging current by hardware interrupt circuit in the chip, chip wake-up within 100μs to resume charging when the wake-up condition is met; The detection circuit is integrated in the ASIC, the voltage and temperature detection input end is connected to the positive and negative poles of the battery through the chip pin and internal wire, the current detection input end is connected to the sampling resistor in series in the charging loop, and the output end of the detection circuit is connected to the data input interface of the control module through the internal bus; The input and output ends of the built-in calibration module are connected with the detection circuit and the control module through the internal bus; The input end of the wide voltage adaptation circuit is connected to the external input power supply through the chip power supply pin, and the output end provides working voltage for each module in the chip; The control module exchanges data and transmits control signals with the detection circuit, the built-in calibration module, the power management circuit and the hardware interrupt circuit through the internal bus; The power management circuit is controlled by the control module, and the output is connected to the necessary module and the unnecessary module in the ASIC chip through the internal power supply network, so as to cut off the power supply of the unnecessary module in the standby mode; The signal input end of the hardware interrupt circuit is connected to the voltage comparator output end or the special wake-up signal line in the detection circuit, and the output end is connected to the interrupt request pin of the control module.

2. The low power consumption charging control method of adaptive standby mode according to claim 1, characterized in that: The ASIC integrates the voltage comparator, the analog-digital converter and the control logic unit required for charging control on the same chip substrate through layout and wiring, the input and output pins are distributed around the chip, and the voltage comparator, the analog-digital converter and the control logic unit are connected through metal wires; The input pin of the voltage comparator is directly connected to the external detection circuit, the output pin is connected to the control module through the internal wire, the wire connects the input power supply to the chip power supply pin, the positive and negative poles of the battery to the chip charging input pin, the LED to the state pin and the resistance in series to the ground.

3. The low power consumption charging control method of adaptive standby mode according to claim 1, characterized in that: The wide voltage adaptation circuit realizes power supply processing through the multi-stage voltage stabilization circuit in the chip, the multi-stage voltage stabilization circuit comprises a front-end anti-reverse connection diode circuit, an LC filter circuit and a DC-DC voltage stabilization circuit, the anode of the anti-reverse connection diode circuit is connected to the positive pin of the input power socket through the PCB wire, and the cathode is connected to one end of the inductor of the LC filter circuit through the wire; the other end of the LC filter circuit is connected to one end of the ceramic capacitor and the input pin of the DC-DC voltage stabilization circuit through the wire, and the other end of the ceramic capacitor is connected to the ground through the wire; The DC-DC voltage stabilizing circuit adopts a synchronous step-down topology, the gate of the internal switch tube is connected to the output pin of the PWM control chip through a wire, the power supply pin of the PWM control chip is connected to the cathode of the anti-reverse connection diode through a wire, the feedback pin of the PWM control chip is connected to the voltage dividing circuit of the charging module power input pin through a wire, and the PWM mode dynamically adjusts the duty cycle according to the input voltage and load change.

4. The low power consumption charging control method of adaptive standby mode according to claim 1, characterized in that: In the charging voltage detection, the analog input pin of the 24-bit sigma-delta analog-to-digital converter in the ASIC is connected to the output end of the programmable gain amplifier through a wire, the input end of the programmable gain amplifier is connected to the battery voltage detection line through a wire, and the gain control pin of the programmable gain amplifier is connected to the GPIO pin of the control module through a wire; the control module outputs different level combinations to the GPIO pin according to the battery voltage range, and controls the amplification multiple of the programmable gain amplifier through the internal decoding circuit; The reference voltage pin of the analog-to-digital converter is connected to the output end of the bandgap reference source in the chip through a wire, and the digital output pin of the analog-to-digital converter is connected to the data input interface of the control module through an internal bus; combined with the calibration data of the bandgap reference source and the analog-to-digital converter at different temperatures before leaving the factory, the detection result is adjusted through a digital calibration algorithm.

5. The low power consumption charging control method of adaptive standby mode according to claim 1, characterized in that: In the full-charge shutdown stage, the PWM output pin of the control module is connected to the input end of the drive circuit through a wire, and the output end of the drive circuit is connected to the gate of the power MOSFET of the charging output loop through a wire; the source of the MOSFET is connected to the positive electrode of the charging power supply through a wire, and the drain is connected to the positive electrode of the battery through a wire; In the later stage of the constant-voltage charging stage, the control module continuously reads the current data output by the analog-to-digital converter through an internal bus, and when the current decreases to below 1% of the rated charging current of the battery and lasts for 10 minutes, the control module sends a low-level signal to the drive circuit through the PWM output pin, the drive circuit outputs a low level, and the MOSFET is cut off; the control module outputs a signal to the LED drive circuit through another GPIO pin to control the LED to be extinguished and slowly flashed.

6. The low power consumption charging control method of adaptive standby mode according to claim 1, wherein: The source of the PMOS switch tube of the power management circuit is connected to the chip power input pin through a wire, and the drain is connected to the power input pins of the unnecessary modules through wires; in the standby mode, the control module sends a low-level signal to the PMOS gate through the internal drive circuit, and the power supply pin of the analog-to-digital converter is connected to a turn-off power switch through a wire; The power supply pin of the voltage comparator is connected to the low-power LDO voltage regulator output end in the chip through a wire, the LDO input is connected to the chip power supply, and the output end is connected to the power supply pin of the voltage comparator and the control module circuit through a wire; when the logic unit in the control module enters the sleep state in the standby mode, the power supply pins of the processing unit and the register are connected to the LDO voltage regulator output end through independent low-power lines.

7. The low power consumption charging control method of adaptive standby mode according to claim 1, wherein: The positive and negative input ends of the current detection amplifier in the ASIC are connected to the two ends of the sampling resistor through wires, the sampling resistor is connected in series in the charging loop, and the output end of the current detection amplifier is connected to the external interrupt pin of the control module through a wire. When the voltage difference across the sampling resistor exceeds the short-circuit threshold, the current detection amplifier outputs a high-level signal to the control module interrupt pin, and the control module sends a control signal to the drive circuit through the internal bus within 20 μs to turn off the charging output drive circuit. The control module starts an internal 1 s timer, and the sampling resistor voltage difference is higher than the threshold within 1 s. The control module cuts off the power supply of the unnecessary circuit through the power management circuit.

8. The low power consumption charging control method of adaptive standby mode according to claim 1, wherein: The detection lines of the negative electrode and the positive electrode of the battery are connected to the input end of the under-voltage protection detection circuit through wires. When the battery voltage is lower than the under-voltage threshold, the under-voltage protection detection circuit sends a low-level signal to the control module interrupt pin through wires. The control module calls the trickle charging program through the internal bus. The PWM output pin of the trickle charging program sends a duty cycle signal to the drive circuit to perform trickle charging at 5% of the rated charging current of the battery. If the battery voltage remains below the under-voltage threshold for 10 minutes, the control module determines that the battery is abnormal and cuts off the power supply of the trickle charging circuit through the power management circuit. When the voltage monitoring circuit powered by an independent low-power power supply detects that the battery voltage has recovered to above the under-voltage threshold, the control module wakes up the battery through the hardware interrupt circuit.

9. The low power consumption charging control method of adaptive standby mode according to claim 1, wherein: The output end of the in-chip temperature sensor is connected to the ADC input pin of the control module through wires. The control pin of the clock generator is connected to the control module. The input end of the heat dissipation control circuit is connected to the control module. The output end of the heat dissipation control circuit is connected to the chip heat dissipation pin drive circuit through wires; When the control module reads a temperature value that exceeds a preset threshold, it sends a signal to the power management circuit and the heat dissipation control circuit through the internal bus. The power management circuit reduces the module operating frequency by adjusting the output frequency of the clock generator.

10. The low power consumption charging control method of adaptive standby mode according to claim 1, wherein: The control module interrupt pin is connected to the output end of the VCC over-voltage protection detection circuit. The input end of the VCC over-voltage protection detection circuit is connected to the chip VCC power pin through wires. When the detected VCC voltage exceeds the preset over-voltage value, the detection circuit sends a high-level signal to the control module interrupt pin through wires. The control module cuts off the MOSFET switch of the charging input loop through the drive circuit. The control module outputs an alarm signal through another GPIO pin. When the detection circuit continuously monitors and sends a low-level signal to the control module interrupt pin to show that the VCC voltage has returned to the normal range, the control module timer delays for 500 ms. The control module wakes up and re-detects the input voltage through the interrupt and restores the charging.

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