CN205862296U - A single-chip microcomputer under-voltage reset circuit - Google Patents

Abstract

The utility model discloses a singlechip under-voltage reset circuit, including resistance R1, diode D1, resistance R2, electric capacity C1 and triode VT1, power VC is connected respectively to resistance R one end, triode VT1 projecting pole and singlechip power end, grounding diode D1 negative pole and resistance R2 are connected respectively to the resistance R1 other end, triode VT1 base is connected to the resistance R2 other end, grounding resistance R4 and resistance R3 are connected respectively to triode VT1 collecting electrode, the reset end of grounding capacity C1 and singlechip is connected respectively to the resistance R3 other end. The utility model discloses singlechip under-voltage reset circuit adopts triode cooperation zener diode to control, effectively makes reset voltage reach stable state, has avoided the release problem about the electric charge in the electric capacity among the traditional reset circuit.

Description

A single-chip microcomputer under-voltage reset circuit

technical field

The utility model relates to a reset circuit, in particular to a single chip microcomputer undervoltage reset circuit.

Background technique

The reset circuit in the prior art is usually composed of two capacitors and a resistance connection. The reset circuit with the above structure has the following disadvantages: since the reset circuit does not have a reset delay, that is, the charge in the capacitor is released through the delay, so if If the charge in the capacitor is not completely released, it will inevitably affect the next reset, thereby affecting the working reliability of the reset circuit.

Utility model content

The purpose of this utility model is to provide a single-chip microcomputer under-voltage reset circuit to solve the problems raised in the above-mentioned background technology.

In order to achieve the above object, the utility model provides the following technical solutions:

A microcontroller undervoltage reset circuit, comprising a resistor R1, a diode D1, a resistor R2, a capacitor C1 and a transistor VT1, one end of the resistor R is respectively connected to a power supply VC, the emitter of the transistor VT1 and the power supply terminal of the microcontroller, and the other end of the resistor R1 is respectively connected to ground The cathode of diode D1 and resistor R2, the other end of resistor R2 is connected to the base of triode VT1, the collector of triode VT1 is respectively connected to grounding resistor R4 and resistor R3, and the other end of resistor R3 is connected to grounding capacitor C1 and the reset terminal of the microcontroller.

As a further solution of the present invention: the diode D1 is a Zener diode.

As a further solution of the utility model: the voltage of the power supply VCC is 5V.

As a further solution of the present invention: the voltage stabilization value of the diode D1 is 3.7V.

Compared with the prior art, the beneficial effect of the utility model is that the undervoltage reset circuit of the single chip microcomputer of the utility model adopts a triode to cooperate with a Zener diode to control, effectively making the reset voltage reach a stable state, and avoiding the problem of electric charge in the capacitor in the traditional reset circuit release problem.

Description of drawings

Fig. 1 is the circuit diagram of the undervoltage reset circuit of the one-chip computer.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

Please refer to Fig. 1, in the embodiment of the present utility model, a single-chip microcomputer undervoltage reset circuit includes a resistor R1, a diode D1, a resistor R2, a capacitor C1 and a triode VT1, and one end of the resistor R is respectively connected to the power supply VC and the emitter of the triode VT1 The other end of the resistor R1 is connected to the negative pole of the grounding diode D1 and the resistor R2, the other end of the resistor R2 is connected to the base of the triode VT1, the collector of the triode VT1 is connected to the grounding resistor R4 and the resistor R3, and the other end of the resistor R3 is connected to the grounding capacitor C1 and the reset terminal of the single-chip microcomputer; the diode D1 is a Zener diode; the voltage of the power supply VCC is 5V; the stabilized voltage value of the diode D1 is 3.7V.

The working principle of the utility model is: please refer to Fig. 1, the 5V voltage starts to rise from "0V", and before rising to 3.6V, the Zener diode D1 is in the cut-off state, VT1 is also in the cut-off state, and there is no reset voltage output. When the +5V power supply voltage is higher than 3.6V, the Zener diode D1 reversely breaks down, and the voltage at both ends of it is "clamped" at 3.6V. When the +5V power supply voltage is higher than 4.3V, VT1 starts to conduct and reset The voltage begins to form. When the +5V power supply voltage is close to +5V, D1 has been saturated and turned on, and the reset voltage reaches a stable state.

It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from all points of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, so it is intended to fall within the scope of the claims All changes within the meaning and range of equivalents of the required elements are included in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only contains an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

Claims (4)

1. a single-chip microcomputer undervoltage reset circuit, comprising resistance R1, diode D1, resistance R2, electric capacity C1 and triode VT1, it is characterized in that, described resistance R one end connects power supply VC, triode VT1 emitter and single-chip microcomputer power terminal respectively, resistance The other end of R1 is connected to the negative pole of the grounding diode D1 and the resistor R2, the other end of the resistor R2 is connected to the base of the triode VT1, the collector of the triode VT1 is respectively connected to the grounding resistor R4 and the resistor R3, and the other end of the resistor R3 is respectively connected to the grounding capacitor C1 and the reset terminal of the microcontroller . 2. The microcontroller undervoltage reset circuit according to claim 1, wherein the diode D1 is a Zener diode. 3. The microcontroller undervoltage reset circuit according to claim 1, wherein the voltage of the power supply VCC is 5V. 4. The microcontroller undervoltage reset circuit according to claim 1, characterized in that, the voltage regulation value of the diode D1 is 3.7V.