CN-115579854-B - MCU port protection circuit

CN115579854BCN 115579854 BCN115579854 BCN 115579854BCN-115579854-B

Abstract

The invention discloses an MCU port protection circuit, which relates to the technical field of power electronics and comprises an input module, a power clamp processing module, a leakage protection module, an input filtering module, an input clamp module, an overvoltage judging module, an MCU module, a protection control module and an overvoltage leakage protection module, wherein the input module is used for transmitting data signals, the power clamp processing module is used for clamping and static detection, the leakage protection module is used for leakage protection, the input filtering module is used for filtering signals, the input clamp module is used for inputting clamps, the overvoltage judging module is used for overvoltage judgment, the MCU module is used for receiving signals, and the protection control module is used for overvoltage leakage protection. The MCU port protection circuit detects transient changes of data signals output by the input module, and improves the protection level of the MCU module to static electricity by performing leakage processing by the leakage protection module, and meanwhile, performs filtering clamping processing and overvoltage judging processing on the data signals input by the MCU module, and performs leakage protection by controlling the protection control module during overvoltage.

Inventors

LV XIANGDONG
WANG AN
TANG WEITONG

Assignees

恒烁半导体(合肥)股份有限公司

Dates

Publication Date: 20260508
Application Date: 20221031

Claims (6)

1. An MCU port protection circuit is characterized in that, The MCU port protection circuit comprises an input module, a power supply clamping processing module, a leakage protection module, an input filtering module, an input clamping module, an overvoltage judging module, an MCU module and a protection control module; the input module is used for receiving data signals transmitted by external equipment through an input port; The power supply clamping processing module is connected with the input module and is used for clamping the data signals transmitted by the input module through the power tube circuit, detecting transient changes between output ends of the input module and outputting a first control signal; The leakage protection module is connected with the power supply clamping processing module and the MCU module, and is used for receiving the first control signal and performing leakage protection control through the bipolar transistor circuit and transmitting the first control signal to the MCU module through the triode circuit; The input filter module is connected with the input module and the MCU module and is used for carrying out filter processing on the data signals output by the input module through the RC filter circuit; The input clamping module is connected with the input filtering module and is used for clamping and outputting the filtered data signals through a three-terminal double-diode circuit; The overvoltage judging module is connected with the input clamping module and is used for judging the overvoltage of the data signal output by the input clamping module and outputting a protection signal; The MCU module is connected with the overvoltage judging module and used for receiving the protection signal and the first control signal and receiving the data signal transmitted by the input filtering module through the MCU interface circuit and the input protection circuit; The protection control module, the input module and the overvoltage judging module are used for receiving the protection signal and controlling the operation of the bleeder circuit through the logic self-locking circuit, and the protection control module is used for performing bleeder processing on the data signal output by the input module through the bleeder circuit; The input filter module comprises a second resistor, a first capacitor, a second capacitor and a third resistor; The first end of the input port is connected with the first end of the second resistor, the second end of the input port is connected with the first end of the third resistor, the second end of the third resistor is connected with one end of the second capacitor, the second end of the second resistor is connected with one end of the first capacitor, and the other end of the first capacitor and the other end of the second capacitor are grounded; The power supply clamping processing module comprises a third power tube, an analog switch, a fourth power tube, a fifth power tube and a sixth power tube; The grid electrode of the fifth power tube is connected with the source electrode of the fourth power tube and the first end and the second end of the analog switch, the fourth end and the third end of the analog switch are respectively connected with the first end and the second end of the input port, the drain electrode of the fifth power tube is connected with the ground end, the source electrode of the fifth power tube is connected with the grid electrode of the fourth power tube, the grid electrode of the third power tube and the drain electrode of the sixth power tube, the source electrode of the third power tube is connected with the drain electrode of the fourth power tube, the drain electrode of the third power tube is connected with the grid electrode of the sixth power tube and the drain protection module, and the source electrode of the sixth power tube is connected with the drain protection module; The leakage protection module comprises a first power tube, a second power tube and a second switch tube; The grid electrode of the first power tube and the grid electrode of the second power tube are both connected with the drain electrode of the third power tube, the source electrode of the second power tube and the emitter electrode of the second switch tube are both connected with the source electrode of the sixth power tube, the collector electrode of the second switch tube is connected with the source electrode of the first power tube and the grid electrode of the fifth power tube, and the drain electrode of the first power tube is connected with the drain electrode of the second power tube and the base electrode of the second switch tube; The leakage protection module further comprises a first power supply, a first resistor and a first switching tube; The first power supply is connected with a collector electrode of the first switching tube and a first IO end of the first processor through a first resistor, a base electrode of the first switching tube is connected with a drain electrode of the first power tube, and an emitting electrode of the first switching tube is grounded.
2. The MCU port protection circuit of claim 1, wherein the input clamp module comprises a first diode, a second diode, a third capacitor, a fourth capacitor, a third diode, a fourth diode, a fifth capacitor, a sixth capacitor; The cathode of the first diode and the anode of the second diode are both connected with the second end of the second resistor, the cathode of the third diode and the anode of the fourth diode are both connected with the second end of the third resistor, the anode of the first diode is connected with one end of the fourth capacitor and the ground end through the third capacitor, the cathode of the second diode is connected with the other end of the fourth capacitor, the anode of the third diode is connected with one end of the sixth capacitor and the ground end through the fifth capacitor, and the cathode of the fourth diode is connected with the other end of the sixth capacitor.
3. The MCU port protection circuit of claim 2, wherein the overvoltage judging module comprises a first voltage regulator tube, a second voltage regulator tube, a fourth resistor, a fifth resistor, a sixth resistor, and a third switching tube; The cathode of the first voltage stabilizing tube and the anode of the second voltage stabilizing tube are respectively connected with the anode of the first diode and the cathode of the second diode, the anode of the first voltage stabilizing tube is connected with the base electrode of the third switching tube and is connected with the ground end through the fourth resistor, the collector electrode of the third switching tube is connected with the first end of the fifth resistor, the cathode of the second voltage stabilizing tube is connected with the emitter of the third switching tube and is connected with the ground end through the sixth resistor, and the second end of the fifth resistor is connected with the third IO end of the first processor.
4. The MCU port protection circuit of claim 3, wherein the overvoltage judging module further comprises a third voltage regulator tube, a fourth switching tube, a seventh resistor, an eighth resistor and a ninth resistor; The cathode of the third voltage stabilizing tube and the anode of the fourth voltage stabilizing tube are respectively connected with the anode of the third diode and the cathode of the fourth diode, the anode of the third voltage stabilizing tube is connected with the base electrode of the fourth switching tube and is connected with the ground end through a seventh resistor, the cathode of the fourth voltage stabilizing tube is connected with the emitter of the fourth switching tube and is connected with the ground end through a ninth resistor, the collector of the fourth switching tube is connected with the first end of an eighth resistor, and the second end of the eighth resistor is connected with the fourth IO end of the first processor and the protection control module.
5. The MCU port protection circuit of claim 4, wherein the MCU module further comprises a first protection tube, a second protection tube, and an MCU interface; One end of the first protection tube and one end of the second protection tube are respectively connected with the second end of the second resistor and the second end of the third resistor, the other end of the first protection tube and the other end of the second protection tube are respectively connected with the first end and the second end of the MCU interface, and the third end of the MCU interface is connected with the second IO end of the first processor.
6. The MCU port protection circuit of claim 5, wherein the protection control module comprises a second power supply, a sixth switching tube, a fifth switching tube, a tenth resistor, an eleventh resistor, a third power supply, a first control tube, a fifth diode; the base electrode of the sixth switching tube and the collector electrode of the fifth switching tube are connected with the second end of the fifth resistor, the emitter electrode of the sixth switching tube is connected with the second power supply, the collector electrode of the sixth switching tube is connected with the base electrode of the fifth switching tube and connected with one end of the eleventh resistor and the grid electrode of the first control tube through the tenth resistor, the emitter electrode of the fifth switching tube is grounded, the other end of the eleventh resistor is connected with the third power supply, the source electrode of the first control tube is connected with the anode and the ground end of the fifth diode, and the drain electrode of the first control tube is connected with the cathode of the fifth diode and the first end of the input port.

Description

MCU port protection circuit Technical Field The invention relates to the technical field of power electronics, in particular to an MCU port protection circuit. Background Along with popularization of electronic equipment, many electronic equipment is provided with an external interface, an external key and other parts for realizing data interaction, when the electronic equipment is used, an internal MCU (Micro-controller Unit) port is connected with the external equipment through a data signal line, damage of the electronic equipment is easily caused due to static electricity and abnormal voltage fluctuation, the MCU port in the prior art mostly adopts an ESD (electro-static discharge) electrostatic protection circuit and an input overvoltage protection circuit for realizing electrostatic detection protection and overvoltage detection protection on data input into the MCU port, but the ESD electrostatic protection circuit only performs electrostatic protection on electric energy input into the MCU port, the level of static electricity protection is limited, the ESD electrostatic protection circuit is easily damaged by high-level static electricity, and the existing input overvoltage protection circuit mostly adopts a comparison circuit for overvoltage detection protection, so that the circuit structure is tedious and high in power consumption, and needs improvement. Disclosure of Invention The embodiment of the invention provides an MCU port protection circuit for solving the problems in the background technology. According to the embodiment of the invention, an MCU port protection circuit is provided, which comprises an input module, a power clamp processing module, a leakage protection module, an input filter module, an input clamp module, an overvoltage judging module, an MCU module and a protection control module; the input module is used for receiving data signals transmitted by external equipment through an input port; The power supply clamping processing module is connected with the input module and is used for clamping the data signals transmitted by the input module through the power tube circuit, detecting transient changes between output ends of the input module and outputting a first control signal; The leakage protection module is connected with the power supply clamping processing module and the MCU module, and is used for receiving the first control signal and performing leakage protection control through the bipolar transistor circuit and transmitting the first control signal to the MCU module through the triode circuit; The input filter module is connected with the input module and the MCU module and is used for carrying out filter processing on the data signals output by the input module through the RC filter circuit; The input clamping module is connected with the input filtering module and is used for clamping and outputting the filtered data signals through a three-terminal double-diode circuit; The overvoltage judging module is connected with the input clamping module and is used for judging the overvoltage of the data signal output by the input clamping module and outputting a protection signal; The MCU module is connected with the overvoltage judging module and is used for receiving the protection signal and the first control signal and receiving the data signal transmitted by the input filtering module through the MCU interface circuit and the input protection circuit; The protection control module, the input module and the overvoltage judging module are used for receiving the protection signal and controlling the operation of the bleeder circuit through the logic self-locking circuit, and the protection control module is used for performing bleeder processing on the data signal output by the input module through the bleeder circuit. Compared with the prior art, the MCU port protection circuit has the advantages that the power supply clamping processing module detects transient changes of data signals output by the input module, the leakage protection module performs leakage processing, abnormal output data signals caused by electrostatic pulses between electronic equipment outputting the data signals and the ground are avoided, the protection level of the MCU module to static is improved, meanwhile, the data signals input into the MCU module are subjected to filtering clamping processing and overvoltage judging processing, the protection control module is controlled to perform leakage protection during overvoltage, data overvoltage of the input MCU module is avoided, the safety of the MCU module is improved, and the overvoltage judging circuit is simple in structure and low in power consumption. Drawings In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following