Totem pole circuit

A totem pole and circuit technology, applied to logic circuits, electrical components, improved amplifiers to reduce temperature/power supply voltage changes, etc., can solve problems such as unstable waveforms, complex drive circuits, and different temperature characteristics of NPN triodes, etc., to achieve The effect of output waveform stabilization

Pending Publication Date: 2020-07-10

GUANGZHOU ZHONGYIGUANG ELECTRONICS TECH

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AI-Extracted Technical Summary

Problems solved by technology

[0003] However, due to the different temperature characteristics of the NPN transistor and the PNP transistor, the output waveform may become unstable in a high temperature environment.

[0004] Second, refer to figure 2 As shown, in the case of a relatively high input voltage, the conventi...

Abstract

The present invention discloses a totem-pole circuit. The totem-pole circuit comprises a triode Q1, a triode Q2, a diode D1 and a diode D2, wherein the triode Q1 and the diode Q2 are of an NPN type. The collector electrode of the triode Q1 is connected with an input voltage Vin, the input voltage Vin is connected with the base electrode of the triode Q1 through a resistor R1, the base electrode ofthe triode Q1 is connected with the collector electrode of the triode Q2 through a diode D2, and the emitter electrode of the triode Q1 is connected with the collector electrode of the triode Q2 through a diode D1. The base electrode of the triode Q2 inputs a driving pulse signal PWM, the emitter electrode is grounded, and the collector electrode is connected with the driving output end. The circuit provided by the invention has more stable circuit performance in a high-temperature environment, and also has a reverse output function.

Application Domain

Amplifier modifications to reduce temperature/voltage variationAmplifiers with multiple amplifying elements +2

Technology Topic

PhysicsHemt circuits +4

Image

Examples

Experimental program(1)

Example Embodiment

[0022] In the following, the present invention will be further described in conjunction with the drawings and specific implementations. It should be noted that, provided that there is no conflict, the following embodiments or technical features can be combined to form new embodiments. .

[0023] A totem pole circuit has a totem pole output with good stability. At the same time, the circuit has a reverse output function to simplify the drive circuit.

[0024] reference image 3 As shown, the totem pole circuit includes two NPN transistors with the same characteristics, named NPN transistor Q1 and NPN transistor Q2 respectively; secondly, the totem pole circuit also includes two diodes D1 and D2.

[0025] The collector of the NPN transistor Q1 is connected to the input voltage Vin. The input voltage Vin is connected to the base of the NPN transistor Q1 through the resistor R1. The emitter of the NPN transistor Q1 is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the NPN The collector of the transistor Q2 is connected.

[0026] The base of the NPN transistor Q1 is connected to the anode of the diode D2, and the cathode of the diode D2 is connected to the collector of the NPN transistor Q2. The base of the NPN transistor Q2 inputs the driving pulse signal PWM, and its emitter is grounded and connected to the The cathodes of the diode D1 and the diode D2 (that is, the collector of the NPN transistor Q2) are connected to the drive output terminal.

[0027] In this embodiment, the driving pulse signal PWM input to the totem pole circuit is a square wave signal. When the base of the NPN transistor Q2 inputs a low-level signal, the NPN transistor Q2 is cut off. At this time, the collector of the NPN transistor Q2 is high, and the cathode of the diode D2 connected to the collector of the NPN transistor Q2 is the same Is high, making the diode D2 cut off; at this time, the input voltage Vin provides a bias current to the base of the NPN transistor Q1 through the resistor R1, the NPN transistor Q1 is turned on, and the input voltage Vin passes through the set of the NPN transistor Q1 The electrode and the emitter flow through the diode D1, and output a high level from the drive output terminal. The high level voltage is Vin-VCE-VD1, where VCE is the voltage between the collector and the emitter when the NPN transistor Q1 is turned on Voltage, VD1 is the voltage when diode D1 is turned on.

[0028] When the base of the NPN transistor Q2 inputs a high level signal, the NPN transistor Q2 is turned on, the collector of the NPN transistor Q2 is low, and the cathode of the diode D2 connected to the collector of the NPN transistor Q2 is also Low level turns on the diode D2. At this time, the voltage between the base and emitter of the NPN transistor Q1 is: Ube=VD1-VD2-Vbe, it can be seen that Ube is a negative pressure, so the NPN transistor Q1 is cut off State, the circuit output is low at this time; VD2 is the voltage when the diode D2 is conducting.

[0029] It can be seen that the circuit of this embodiment has a reverse output function, that is, when the drive signal is high and low, the output is low and high.

[0030] In addition, when the input voltage is relatively high, this embodiment only needs a simple low-voltage drive signal to drive the NPN transistor Q2. In this embodiment, the driving circuit realizes the function of driving the NPN transistor Q2. Reference Figure 4 As shown, the driving circuit includes a capacitor C1 and a transformer T1. The capacitor C1 is connected to the drive output terminal. The capacitor C1 and the transformer T1 are connected in series and then grounded. According to the above circuit principle, it can be known that the driving circuit can drive the transistor Q2 to turn on, so that the transistor Q1 Cut off; when the drive circuit stops driving the transistor Q2, the transistor Q2 is cut off, so that the transistor Q1 is turned on, further simplifying the circuit.

[0031] The foregoing embodiments are only preferred embodiments of the present invention, and cannot be used to limit the scope of protection of the present invention. Any insubstantial changes and substitutions made by those skilled in the art on the basis of the present invention belong to the present invention. The scope of protection required.

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