Darlington drive circuit with low turn-on voltage

Abstract

The utility model relates to the technical field of Darlington driving circuits, in particular to a low-threshold-voltage Darlington driving circuit, which comprises a transistor T1, a transistor T2, a common end of a clamping diode, a resistor R1, a resistor R2 and a resistor R3. The resistor R1 is connected between the input (B) and the transistor T1; according to the Darlington transistor circuit, the starting voltage of the Darlington transistor circuit can be reduced from more than 2V to a typical value 1.6 V, the Darlington transistor circuit can be further applied under the condition that an input signal is 1.8 V, and the application of the Darlington transistor circuit is greatly expanded.

Description

TECHNICAL FIELD

[0001] The utility model relates to darlington drive circuit technical field especially relates to a low opening voltage's darlington drive circuit. BACKGROUND

[0002] The working principle of darlington transistor circuit is based on the concept of cascade amplification. The input signal is first amplified by the driver transistor, and then further amplified by the output transistor. The structure of this cascade amplification makes the darlington transistor circuit have a high current amplification factor and a low input resistance.

[0003] Specifically, when the input signal is applied to the base of the driver transistor, the driver transistor starts to conduct. After conducting, the current on the collector of the driver transistor will flow into the base of the output transistor, causing the output transistor to also start to conduct. In this way, the current on the collector of the output transistor will be amplified, forming the final output signal.

[0004] Due to its high current amplification factor and low input resistance, the darlington transistor circuit is widely used in many fields;

[0005] The existing darlington transistor opening voltage is generally above 2V, so it cannot be applied to the application of input signal 1.8V. INVENTION CONTENTS

[0006] The utility model discloses a kind of low opening voltage's darlington drive circuit, including T1 transistor, T2 transistor, clamping diode public end, R1 resistance, R2 resistance, R3 resistance;

[0007] The utility model has the following technical scheme: a low opening voltage's darlington drive circuit, including T1 transistor, T2 transistor, clamping diode public end, R1 resistance, R2 resistance, R3 resistance;

[0008] The R1 resistance is connected between input (B) and T1 transistor;

[0009] The R2 resistance is connected between R1 resistance and T2 transistor;

[0010] The R3 resistance is connected between R2 resistance and T2 transistor;

[0011] The T1 transistor is connected to the clamping diode public end;

[0012] The T2 transistor is connected to the public end.

[0013] Preferably, the T1 transistor is also connected with output (C).

[0014] Preferably, the resistance ratio of R2 resistance and R3 resistance is 5.5:4.5.

[0015] Compared with the prior art, the low open voltage Darlington drive circuit has the advantages and positive effects that

[0016] In the utility model, the turn-on voltage of the Darlington transistor circuit can be reduced from 2V to a typical value of 1.6V, and the application of the Darlington transistor circuit to the input signal of 1.8V is further satisfied, and the application of the product is greatly expanded. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The utility model provides a low open voltage's Darlington drive circuit's schematic diagram. DETAILED DESCRIPTION

[0018] In order to more clearly understand the above purpose, features and advantages of the utility model, the utility model is further described below in combination with the drawings and examples.It should be explained that the examples and features in the examples of the present application can be combined with each other without conflict.

[0019] In the following description, a lot of specific details are set forth in order to fully understand the utility model, but the utility model can also be implemented in other ways different from the description, therefore, the utility model is not limited to the specific examples disclosed in the following description.

[0020] Embodiment

[0021] Please refer to Figure 1 The utility model provides a technical scheme: a low open voltage's Darlington drive circuit, including T1 transistor, T2 transistor, clamping diode public end, R1 resistance, R2 resistance, R3 resistance, T1 transistor, T2 transistor mainly plays the role of amplification, and the clamping diode public end plays the role of freewheeling;

[0022] R1 resistance is connected between input (B) and T1 transistor;

[0023] R2 resistance is connected between R1 resistance and T2 transistor;

[0024] R3 resistance is connected between R2 resistance and T2 transistor;

[0025] T1 transistor is connected to the clamping diode public end;

[0026] T2 transistor is connected to the public end;

[0027] T1 transistor is also connected with output (C);

[0028] The resistance ratio of R2 resistance and R3 resistance is 5.5:4.5.

[0029] Working principle: input start voltage can be realized by adjusting R1, R2, R3 resistance, by adjusting, change the voltage between the input and ground (i.e. input signal voltage) on T1 tube and T2 tube on the voltage division ratio, in order to achieve lower voltage T1 tube and T2 tube start, can make the start voltage of Darlington transistor circuit from 2V above to typical value 1.6V, further make it satisfy the application of input signal 1.8V condition, the application of this kind of product is greatly expanded.

[0030] The above is only the preferred embodiment of the present application, and is not intended to limit the present application in other forms. Any skilled person in the art can modify or change the above disclosed technology content to equivalent embodiments applied to other fields. However, any simple modification, equivalent change and modification made to the above embodiments without departing from the technical solution of the present application, and in accordance with the technical essence of the present application, still belong to the protection scope of the present application.

Claims

1. A Darlington drive circuit with low turn-on voltage, characterized in that, The T1 transistor, the T2 transistor, the common end of the clamping diode, the R1 resistor, the R2 resistor and the R3 resistor are included. The R1 resistor is connected between the input (B) and the T1 transistor. The R2 resistor is connected between the R1 resistor and the T2 transistor. The R3 resistor is connected between the R2 resistor and the T2 transistor. The T1 transistor is connected to the common end of the clamping diode. The T2 transistor is connected to the common end.

2. The low-ON voltage Darlington driver circuit of claim 1, wherein: The T1 transistor is further connected with the output (C).

3. The low-ON voltage Darlington driver circuit of claim 1, wherein: The resistance ratio of the R2 resistor and the R3 resistor is 5.5:4.5.

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