CN-114977092-B - Input voltage overvoltage and undervoltage protection module, power supply system and chip

Abstract

The invention provides an input voltage overvoltage and undervoltage protection module, a power supply system and a chip, which comprise a first comparison unit, a second comparison unit, an initial state detection comparison unit, a power frequency period peak value detection comparison unit and a protection control unit, wherein the first comparison unit compares a bus voltage detection voltage with an overvoltage protection reference voltage and generates an overvoltage protection signal, the second comparison unit compares the detection voltage with the undervoltage protection reference voltage and generates an undervoltage detection signal, the initial state detection comparison unit generates a first undervoltage protection signal when the undervoltage detection signal is effective in an initial power supply voltage acquisition stage, the power frequency period peak value detection comparison unit generates a second undervoltage protection signal after the undervoltage detection signal is effective for a preset time, and the protection control unit generates a protection control signal. The invention has no requirement on ripple wave of bus voltage, can accurately detect input voltage, effectively protects a power supply system, has simple circuit, saves space and cost, has high response speed when in input overvoltage protection, has high accuracy when in input undervoltage protection, and also has undervoltage response speed in the initial state of the system.

Inventors

• SHENG HUAN
• LI LIANG
• LIN CHANGQUAN

Assignees

• 华润微集成电路(无锡)有限公司

Dates

Publication Date

20260512

Application Date

20210218

Claims (10)

1. 1. The utility model provides an input voltage overvoltage under-voltage protection module which characterized in that, input voltage overvoltage under-voltage protection module includes at least: The first comparison unit receives the detection voltage of the bus voltage and the overvoltage protection reference voltage, and generates an overvoltage protection signal based on the comparison result of the detection voltage and the overvoltage protection reference voltage; The second comparison unit receives the detection voltage and the undervoltage protection reference voltage and generates an undervoltage detection signal based on a comparison result of the detection voltage and the undervoltage protection reference voltage; The initial state detection comparison unit is connected to the output end of the second comparison unit, receives a power supply voltage to obtain an electric signal, and generates a first undervoltage protection signal when the undervoltage detection signal is effective in the initial stage of power supply voltage obtaining; The power frequency period peak detection comparison unit is connected to the output end of the second comparison unit, receives the power supply voltage to obtain an electric signal, and generates a second undervoltage protection signal when the effective time of the undervoltage detection signal reaches a preset time after the power supply voltage is electrified; the power frequency period peak detection comparison unit comprises an oscillator and a counter, wherein the input end of the oscillator receives the power supply voltage to obtain an electric signal, and generates an oscillation signal based on the power supply voltage to obtain the electric signal; The protection control unit is connected to the output ends of the first comparison unit, the initial state detection comparison unit and the power frequency period peak value detection comparison unit, and generates a protection control signal when the overvoltage protection signal, the first undervoltage protection signal or the second undervoltage protection signal is effective.
2. 2. The module of claim 1, wherein the non-inverting input terminal of the first comparator receives the detection voltage, the inverting input terminal receives the reference voltage, and outputs the over-voltage protection signal.
3. 3. The module of claim 1, wherein the second comparator has an inverting input coupled to the detection voltage and a non-inverting input coupled to the undervoltage reference voltage and outputting the undervoltage detection signal.
4. 4. The module of claim 1, wherein the protection signal generating unit comprises an OR gate and a protection control signal generating circuit; The first input end of the OR gate is connected with the output end of the first comparison unit, the second input end of the OR gate is connected with the output end of the initial state detection comparison unit, the third input end of the OR gate is connected with the output end of the power frequency period peak value detection comparison unit, and OR operation is carried out on the overvoltage protection signal, the first undervoltage protection signal and the second undervoltage protection signal; The protection control signal generating circuit is connected to the output end of the OR gate and generates the protection control signal based on the output signal of the OR gate.
5. 5. The input voltage overvoltage and undervoltage protection module according to claim 1, further comprising a logic control unit and a driving unit, wherein the logic control unit is connected to an output end of the protection control unit, generates a switch control signal based on the protection control signal, and the driving unit is connected to an output end of the logic control unit.
6. 6. The module for protecting against overvoltage and undervoltage of input voltage according to any one of claims 1 to 5, wherein the initial state detection and comparison unit comprises a current source, a first switch, a second switch, a first capacitor, an inverter and an AND gate; One end of the current source is connected with working voltage, and the other end of the current source is connected with an upper polar plate of the first capacitor through the first switch; the second switch is connected in parallel with two ends of the first capacitor, and the control end receives an inverted signal of the electric signal obtained by the power supply voltage; The input end of the inverter is connected with the upper polar plate of the first capacitor, the output end of the inverter is connected with the first input end of the AND gate, and the second input end of the AND gate receives the undervoltage detection signal and outputs the first undervoltage protection signal.
7. 7. A power supply system, the power supply system comprising at least: The voltage input module receives alternating input voltage and converts the alternating input voltage into bus voltage; The sampling module is connected with the output end of the voltage input module and is used for sampling the bus voltage to obtain detection voltage; The power supply voltage detection module is used for detecting the power supply voltage and outputting the power supply voltage to obtain an electric signal; The input voltage overvoltage and undervoltage protection module according to any one of claims 1-6, which is connected to an output end of the sampling module and generates a switch control signal based on the detection voltage and an electric signal obtained by the power supply voltage; and the control end receives the switch control signal and protects the overvoltage and the undervoltage of the input voltage based on the switch control signal.
8. 8. The power supply system according to claim 7, wherein the voltage input module comprises a rectifying unit and an electrolytic capacitor, and the electrolytic capacitor is connected in parallel with an output end of the rectifying unit.
9. 9. The power supply system of claim 8, wherein the sampling module comprises a first sampling resistor and a second sampling resistor, a first end of the first sampling resistor is connected with the output end of the voltage input module, a second end of the first sampling resistor is connected with the first end of the second sampling resistor and outputs the detection voltage, and a second end of the second sampling resistor is grounded.
10. 10. A chip, characterized in that the chip at least comprises the input voltage overvoltage and undervoltage protection module according to any one of claims 1-6.

Description

Input voltage overvoltage and undervoltage protection module, power supply system and chip Technical Field The present invention relates to the field of circuit design, and in particular, to an input voltage overvoltage and undervoltage protection module, a power supply system, and a chip. Background The power supply system provides power for various electric equipment, and reducing the influence of input voltage on the power supply system and maintaining the stable operation of the electric equipment are vital links in power management. In the conventional power supply system, when the input voltage needs to be protected when it is too high or too low, the input voltage is usually detected in real time by detecting the rectified bus voltage. The detection mode can only be used for a power supply system with small ripple of the bus voltage, so that the electrolytic capacitor at the input end after rectification is required to be large enough, and the system load cannot be excessively heavy, so that the ripple voltage on the electrolytic capacitor is reduced. However, the large electrolytic capacitor not only increases the cost, but also occupies the space of the peripheral circuit, and the requirement on the system load limits the application range of the detection mode. Therefore, how to perform overvoltage and undervoltage protection on the power supply system on the basis of saving space and cost and expanding application range has become one of the problems to be solved by those skilled in the art. Disclosure of Invention In view of the above-mentioned drawbacks of the prior art, the present invention is directed to providing an input voltage overvoltage/undervoltage protection module, a power supply system and a chip, which are used for solving the problems of high cost, large occupied peripheral space, small application range and the like in the prior art. To achieve the above and other related objects, the present invention provides an input voltage overvoltage/undervoltage protection module, which at least includes: The first comparison unit receives the detection voltage of the bus voltage and the overvoltage protection reference voltage, and generates an overvoltage protection signal based on the comparison result of the detection voltage and the overvoltage protection reference voltage; The second comparison unit receives the detection voltage and the undervoltage protection reference voltage and generates an undervoltage detection signal based on a comparison result of the detection voltage and the undervoltage protection reference voltage; The initial state detection comparison unit is connected to the output end of the second comparison unit, receives a power supply voltage to obtain an electric signal, and generates a first undervoltage protection signal when the undervoltage detection signal is effective in the initial stage of power supply voltage obtaining; the power frequency period peak detection comparison unit is connected to the output end of the second comparison unit, receives the power supply voltage to obtain an electric signal, and generates a second undervoltage protection signal when the effective time of the undervoltage detection signal reaches a preset time after the power supply voltage is electrified; The protection control unit is connected to the output ends of the first comparison unit, the initial state detection comparison unit and the power frequency period peak value detection comparison unit, and generates protection control signals based on the overvoltage protection signals, the first undervoltage protection signals and the second undervoltage protection signals. Optionally, the non-inverting input end of the first comparing unit receives the detection voltage, the inverting input end receives the overvoltage protection reference voltage, and outputs the overvoltage protection signal. More optionally, an inverting input end of the second comparing unit is connected with the detection voltage, and a non-inverting input end receives the undervoltage protection reference voltage and outputs the undervoltage detection signal. Optionally, the protection signal generating unit includes an or gate and a protection control signal generating circuit; The first input end of the OR gate is connected with the output end of the first comparison unit, the second input end of the OR gate is connected with the output end of the initial state detection comparison unit, the third input end of the OR gate is connected with the output end of the power frequency period peak value detection comparison unit, and OR operation is carried out on the overvoltage protection signal, the first undervoltage protection signal and the second undervoltage protection signal; The protection control signal generating circuit is connected to the output end of the OR gate and generates the protection control signal based on the output signal of the OR gate. Optionally, the input voltage overvoltage an