Reset circuit using field effect transistor and triode

Abstract

The utility model provides a reset circuit using a field effect transistor and a triode, which belongs to the technical field of reset circuits and comprises a power input end, a reset circuit control module and a reset circuit starting module, the power input end is connected with the reset circuit control module and the reset circuit starting module, and the field effect transistor and the triode are connected with the reset circuit starting module. The output end of the reset circuit control module is connected with the input end of the reset circuit starting module, and the output end of the reset circuit starting module is connected with the input end of the microcontroller. The power supply input end inputs a power supply to the reset circuit control module, the reset circuit control module outputs a control signal to the reset circuit starting module, and the reset circuit starting module outputs a reset signal to the microcontroller. According to the utility model, the working stability of the reset circuit is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of reset circuit, specifically, the utility model relates to a reset circuit using field effect tube and triode. BACKGROUND

[0002] Generally speaking, MCU reset circuit mainly has four types: differential type reset circuit, integral type reset circuit, comparator type reset circuit, watchdog type reset circuit. The traditional MCU reset circuit usually uses differential type reset circuit and integral type reset circuit. With the MCU system more and more complex, the application environment more and more diversification, the traditional MCU reset circuit in some applications already can not satisfy the level and time sequence requirement of MCU reset, for the application in the system that requires more rigorous MCU reset circuit is more and more urgent.

[0003] Chinese patent 210627124U discloses the utility model relates to a watchdog recovery circuit;When the microcontroller works normally, the microcontroller's feeding dog pin outputs normal feeding dog signal to the watchdog circuit, wherein the normal feeding dog signal is outputted high level or low level according to the set time interval, and the watchdog circuit continues to maintain the on state of the switch circuit after receiving the normal feeding dog signal;When the microcontroller works abnormally, the microcontroller's feeding dog pin outputs abnormal feeding dog signal to the watchdog circuit, wherein the abnormal feeding dog signal is not outputted high level or low level according to the set time interval or no level output, and the watchdog circuit controls the switch circuit to cut off after receiving the abnormal feeding dog signal for a certain time to restore the on state, so as to power off reset to the microcontroller.

[0004] The prior art circuit structure is complex, and the working stability is poor, which can not meet the demand of microcontroller reset at present. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a reset circuit using field effect tube and triode, to achieve the technical purpose of improving the working stability of microcontroller.

[0006] In order to realize the above-mentioned purpose, the technical scheme adopted by the utility model is:

[0007] The utility model provides a reset circuit using field effect tube and triode, including power input, reset circuit control module and reset circuit starting module, the power input connects reset circuit control module, the power input connects reset circuit starting module, the output of reset circuit control module connects the input of reset circuit starting module, and the output of reset circuit starting module connects the input of microcontroller.

[0008] The power input end inputs power to the reset circuit control module, the reset circuit control module outputs a control signal to the reset circuit starting module, and the reset circuit starting module outputs a reset signal to the microcontroller.

[0009] The power input end comprises a first power input end and a second power input end.

[0010] The reset circuit control module comprises a current-limiting resistor, a stabilizing tube, an energy storage capacitor, a pull-down resistor, a field effect tube and a triode.

[0011] The first power input end is connected with the current-limiting resistor, one end of the current-limiting resistor is connected with the cathode of the stabilizing tube, one end of the stabilizing tube is connected with one end of the energy storage capacitor, the other end of the energy storage capacitor is grounded, the anode of the stabilizing tube is connected with one end of the pull-down resistor, the other end of the pull-down resistor is grounded, the anode of the stabilizing tube is connected with the gate of the field effect tube, the source of the field effect tube is grounded, the drain of the field effect tube is connected with the base of the triode, the emitter of the triode is connected with the second power input end, and the collector of the triode is connected with the input end of the reset circuit starting module.

[0012] The base of the triode is connected with the emitter of the triode through a first resistor.

[0013] The drain of the field effect tube is connected with the base of the triode through a second resistor.

[0014] The reset circuit starting module comprises a pull-up resistor, a reset capacitor and a Schottky diode.

[0015] The output end of the reset circuit control module is connected with one end of the pull-up resistor, the other end of the pull-up resistor is connected with the anode of the Schottky diode, the cathode of the Schottky diode is connected with the second power input end, the anode of the Schottky diode is connected with one end of the reset capacitor, the other end of the reset capacitor is grounded, and the anode of the Schottky diode is connected with the input end of the microcontroller.

[0016] The technical effect of the utility model is:

[0017] (1) The conduction and cut-off of the field effect tube and the triode in the reset circuit control module make the reset signal start to pull high and release after the power is stable during power-on, and the reset signal can also stably and rapidly drop to 0V during power-off, thereby improving the reliability of system work.

[0018] (2) The utility model has simple structure, low failure rate and reduced cost. BRIEF DESCRIPTION OF DRAWINGS

[0019] The present specification comprises the following drawings, and the shown contents are as follows:

[0020] Figure 1The utility model provides a reset circuit's logic structure block diagram of using field effect tube and triode,

[0021] Figure 2 The utility model provides a reset circuit's circuit diagram of using field effect tube and triode,

[0022] Figure 1 The middle mark is: 1, power input end, 2, reset circuit control module, 3, reset circuit starting module. Specific embodiments

[0023] The specific embodiments of the utility model are further explained in detail below by the description of the embodiments with reference to the drawings, the purpose is to help the technical personnel in the field to the utility model concept, technical scheme of the utility model have more complete, accurate and thorough understanding, and help its implementation.

[0024] The utility model provides a reset circuit's logic structure block diagram of using field effect tube and triode,

[0025] The power input end 1 includes the first power input end (VBAT D) and the second power input end (VCC 5V).

[0026] The reset circuit control module 2 includes the current -limiting resistance (R1161), the stabilivolt (Z2), the energy storage capacitor (C587), the pull -down resistance (R1162), the field effect tube (Q41) and the triode (Q40).

[0027] The first power input terminal (VBAT_D) is connected to a current-limiting resistor (R1161). The other end of the current-limiting resistor (R1161) is connected to the cathode of the Zener diode (Z2). The anode of the Zener diode (Z2) is connected to one end of the energy storage capacitor (C587), and the other end of the energy storage capacitor (C587) is grounded. The anode of the Zener diode (Z2) is connected to one end of the pull-down resistor (R1162), and the other end of the pull-down resistor (R1162) is grounded. The anode of the Zener diode (Z2) is connected to the gate of the field-effect transistor (Q41). The source of the field-effect transistor (Q41) is grounded. The drain of the field-effect transistor (Q41) is connected to the base of the transistor. The emitter of the transistor is connected to the second power input terminal (VCC_5V). The collector of the transistor is connected to the input terminal of the reset circuit startup module 3. The base of the transistor is connected to the emitter of the transistor (Q40) through the first resistor (R1). The drain of the field-effect transistor (Q41) is connected to the base of the transistor through a second resistor (R2). In this embodiment of the invention, the first resistor (R1) is 47kΩ and the second resistor (R2) is 10kΩ.

[0028] The reset circuit startup module 3 includes a pull-up resistor (R1160), a reset capacitor (C586), and a Schottky diode (D79). The output terminal of the reset circuit control module 2 is connected to one end of the pull-up resistor (R1160), and the other end of the pull-up resistor (R1160) is connected to the anode of the Schottky diode (D79). The cathode of the Schottky diode (D79) is connected to the second power input terminal (VCC_5V), the anode of the Schottky diode (D79) is connected to one end of the reset capacitor (C586), the other end of the reset capacitor (C586) is grounded, and the anode of the Schottky diode (D79) is connected to the input terminal of the microcontroller.

[0029] The following is combined with Figure 2 The circuit diagram is described in detail below.

[0030] This utility model discloses a reset circuit using a field-effect transistor (Q41) and a transistor, comprising a power input terminal 1, a reset circuit control module 2, and a reset circuit startup module 3. The power input terminal 1 includes a first power input terminal (VBAT_D) and a second power input terminal (VCC_5V). The second power input terminal (VCC_5V) is derived from the first power input terminal (VBAT_D) via a DC / DC converter. Both power input terminals provide reliable power to meet the microcontroller's requirements for the RESET signal level.

[0031] The reset circuit control module 2 comprises a current-limiting resistor (R1161), a voltage stabilizing tube (Z2), an energy storage capacitor (C587), a pull-down resistor (R1162), a field effect tube (Q41) and a triode (Q40). The current-limiting resistor (R1161) is used for limiting the current flowing through the voltage stabilizing tube (Z2) to prevent the voltage stabilizing tube (Z2) from being burned out due to thermal breakdown caused by excessive current. The current-limiting resistor (R1161) in the embodiment of the utility model is 10kΩ. The voltage stabilizing tube (Z2) is used for providing a certain threshold voltage for the reset circuit control module 2. When the voltage on the first power input end (VBAT_D) starts to rise to be greater than the voltage stabilizing value of the voltage stabilizing tube (Z2), the voltage stabilizing tube (Z2) starts to be reversely broken down and conducted. The voltage stabilizing tube (Z2) in the embodiment of the utility model is BZT52B5V1. The energy storage capacitor (C587) is used for stabilizing the gate level signal of the field effect tube (Q41) when the power voltage fluctuates. The energy storage capacitor (C587) in the embodiment of the utility model is 4.7uF. The pull-down resistor (R1162) is used for providing a stable low level for the gate of the field effect tube (Q41) at the initial stage of power-on, and providing a discharge circuit for the energy storage capacitor (C587). The pull-down resistor (R1162) in the embodiment of the utility model is 10kΩ. The field effect tube (Q41) and the triode (Q40) jointly act. When the field effect tube (Q41) and the triode (Q40) are both conducted, the voltage of the second power input end (VCC_5V) is output to the reset circuit starting module 3. The field effect tube (Q41) in the embodiment of the utility model is NX7002BKW, and the triode is PDTA114YU.

[0032] The reset circuit starting module 3 comprises a pull-up resistor (R1160), a reset capacitor (C586) and a Schottky diode (D79). The pull-up resistor (R1160) and the reset capacitor (C586) work in cooperation. When power is on, the power charges the reset capacitor (C586) through the pull-up resistor (R1160), so that the signal level of the input end (RESET) of the microcontroller slowly rises. The Schottky diode (D79) is used for rapidly discharging the charge accumulated on the reset capacitor (C586) when power is off. The pull-up resistor (R1160) in the embodiment of the utility model is 10kΩ, the reset capacitor (C586) is 10nF, and the Schottky diode (D79) is SM140WS.

[0033] The specific connection relationship of the utility model is: one end of the first power input end (VBAT_D) is connected with the current-limiting resistor (R1161), the other end of the current-limiting resistor (R1161) is connected with the cathode of the stabilizing tube (Z2), the anode of the stabilizing tube (Z2) is grounded through the energy storage capacitor (C587), the anode of the stabilizing tube (Z2) is grounded through the pull-down resistor (R1162), the anode of the stabilizing tube (Z2) is connected with the gate of the field effect transistor (Q41), the source of the field effect transistor (Q41) is grounded, the drain of the field effect transistor (Q41) is connected with the base of the triode through the second resistor (R2), the emitter of the triode (Q40) is connected with the second power input end (VCC_5V), the base of the triode (Q40) is connected with the emitter of the triode through the first resistor (R1), the collector of the triode is connected with one end of the pull-up resistor (R1160), the other end of the pull-up resistor (R1160) is connected with the anode of the Schottky diode (D79), the anode of the Schottky diode (D79) is grounded through the reset capacitor (C586), the anode of the Schottky diode (D79) is connected with the input end (RESET) of the microcontroller, and the cathode of the Schottky diode (D79) is connected with the second power input end (VCC_5V).

[0034] When working, the reset circuit control module 2 controls the high and low levels of the reset signal output, and the reset circuit starting module 3 makes the reset signal output high and low levels in correct and reasonable time sequence when power-on and power-off.

[0035] The conduction and cut-off of the field effect transistor (Q41) and the triode in the reset circuit control module 2 make the reset signal start to pull high and release only after the power is stable when power-on, and the reset signal can also stably and rapidly drop to 0V when power-off, thereby improving the reliability of circuit work.

[0036] The utility model is described exemplarily above in combination with the drawings. Obviously, the specific implementation of the utility model is not limited by the above mode. As long as various non-essential improvements are made by adopting the method concept and technical scheme of the utility model, or the above-mentioned concept and technical scheme of the utility model are directly applied to other occasions without improvement, all of them are within the protection scope of the utility model.

Claims

1. A reset circuit using field-effect transistors and bipolar transistors, characterized in that: It includes a power input terminal, a reset circuit control module, and a reset circuit startup module. The power input terminal is connected to the reset circuit control module and the reset circuit startup module. The output terminal of the reset circuit control module is connected to the input terminal of the reset circuit startup module, and the output terminal of the reset circuit startup module is connected to the input terminal of the microcontroller.

2. A reset circuit using a field-effect transistor and a bipolar transistor as described in claim 1, characterized in that: The power input terminal supplies power to the reset circuit control module, the reset circuit control module outputs a control signal to the reset circuit startup module, and the reset circuit startup module outputs a reset signal to the microcontroller.

3. A reset circuit using a field-effect transistor and a bipolar transistor as described in claim 1, characterized in that: The power input terminal includes a first power input terminal and a second power input terminal.

4. A reset circuit using a field-effect transistor and a bipolar transistor as described in claim 1, characterized in that: The reset circuit control module includes a current-limiting resistor, a Zener diode, an energy storage capacitor, a pull-down resistor, a field-effect transistor, and a transistor.

5. A reset circuit using a field-effect transistor and a bipolar transistor as described in claim 3, characterized in that: The first power input terminal is connected to a current-limiting resistor, the other end of which is connected to the cathode of a Zener diode. The anode of the Zener diode is connected to one end of an energy storage capacitor, the other end of which is grounded. The anode of the Zener diode is connected to one end of a pull-down resistor, the other end of which is grounded. The anode of the Zener diode is connected to the gate of a field-effect transistor (FET), the source of the FET is grounded, the drain of the FET is connected to the base of a transistor, the emitter of the transistor is connected to the second power input terminal, and the collector of the transistor is connected to the input terminal of the reset circuit startup module.

6. A reset circuit using a field-effect transistor and a bipolar transistor as described in claim 4, characterized in that: The base of the transistor is connected to the emitter of the transistor through a first resistor.

7. A reset circuit using a field-effect transistor and a bipolar transistor as described in claim 5, characterized in that: The drain of the field-effect transistor is connected to the base of the transistor through a second resistor.

8. A reset circuit using a field-effect transistor and a bipolar transistor as described in claim 1, characterized in that: The reset circuit startup module includes a pull-up resistor, a reset capacitor, and a Schottky diode.

9. A reset circuit using a field-effect transistor and a bipolar transistor as described in claim 1, 3, or 8, characterized in that: The output terminal of the reset circuit control module is connected to one end of a pull-up resistor, the other end of the pull-up resistor is connected to the anode of a Schottky diode, the cathode of the Schottky diode is connected to the second power input terminal, the anode of the Schottky diode is connected to one end of a reset capacitor, the other end of the reset capacitor is grounded, and the anode of the Schottky diode is connected to the input terminal of the microcontroller.

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