KR100581003B1 - Switching circuit - Google Patents

Abstract

The present invention relates to a switching driving circuit composed of a plurality of transistors, which can prevent malfunction due to the thermal runaway phenomenon generated in the transistor, reduce power consumption, and obtain a low ripple voltage. And a switch driving controller for stably performing a switching operation by preventing an overcurrent from being generated at the input terminal and a circuit to which a signal is input, and an output terminal for outputting a signal received from the switch driving controller. The stable output voltage can be obtained by preventing the occurrence of overcurrent, and the reliability of the product can be improved by reducing the magnitude of the output ripple voltage.

Switching drive circuit, switch, transistor

Description

 Switching circuit             

1 is a view showing a switching driving circuit according to the prior art,

2 is a diagram illustrating a switching driving circuit according to the present invention.

<Explanation of symbols on main parts of the drawings>

10: switch drive control unit 20: control IC

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching driving circuit, and more particularly to a switching driving circuit which prevents a malfunction due to an overcurrent generated during the operation of the circuit.

Hereinafter, a structure and a problem of a switching driving circuit according to the prior art will be described with reference to the accompanying drawings. 1 is a view showing the structure of a switching driving circuit according to the prior art.

1, and a driving control unit for generating a switching operation signal, depending on by the switching drive circuit and an input terminal (V _IN) signal is input, the voltage level of the signal inputted from the input terminal (V _IN), said And an output terminal V _OUT for outputting an operation signal generated from the drive control unit.

The driving control unit is composed of one transistor Q1 to perform a switching operation, wherein the switch driving circuit further includes a reference voltage for determining a voltage level of the switching operation signal output through the output terminal V _OUT . It is configured.

In the switching driving circuit configured as described above, when the voltage of the input terminal V _IN high level is applied, the transistor Q1 is turned on and the reference voltage V _DD is applied to the output terminal V _OUT . When the voltage of the same level as that is output, and a low level voltage is applied to the input terminal V _IN , the transistor Q1 is turned off to output the voltage of OV to the output terminal V _OUT . As a result, a pulse signal capable of performing a switching operation is output from the output terminal V _OUT .

However, the switching driving circuit constructed and operated as described above has a constant size between the reference voltage V _DD , the transistor Q1, and the output terminal V _{OUT when the} transistor Q1 is turned on. Current can be formed.

Therefore, when the current flows in the switching driving circuit, power consumption of that size is increased, and when the current is applied to the transistor Q1, the transistor Q1 is thermally runaway due to overcurrent and malfunctions. Problems will arise.

The present invention has been made to solve the above problems of the prior art, it is composed of a plurality of transistors, it is possible to reduce the power consumption as well as to prevent malfunction caused by the thermal runaway phenomenon occurring in the transistors It is an object of the present invention to provide a switching driving circuit capable of obtaining a ripple voltage.

The switching driving circuit according to the present invention for solving the above problems is a third transistor which is an N type first transistor, a P type second transistor, and an N-channel field effect transistor and the operation of the first and second transistors. And a switch driving control unit having a resistor for supplying a reference voltage to the third transistor, and an output terminal for removing noise and outputting the voltage output through the third transistor.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 2 is a diagram illustrating a switching driving circuit according to the present invention.

As shown in FIG. 2, the switch driving circuit according to the present invention outputs a reference voltage according to on-off operations of a first transistor, a second transistor, and a third transistor operated according to an input pulse signal. And a position driving control unit 10 and an output terminal V _OUT for removing and outputting noise included in a voltage output through the switch driving control unit.

The switching driving circuit further includes a control IC 20 for generating a pulse signal and applying the pulse signal to the input terminal.

The switch driving controller 10 includes first, second, and third transistors, and the first Q11 and the second transistor Q12 have a base connected to the control IC 20. The collector of the first transistor Q11 is connected to the reference voltage V _DD , and the third transistor Q13 has a gate connected to the emitter of the first transistor Q11 and the collector of the second transistor Q12. Connected.
The switch driving controller 10 has a resistor connected in common to the collector and base of the first transistor Q11 and the base of the second transistor Q12.

In addition, the first transistor Q11 is N-type BJT, the second transistor Q12 is P-type BJT, and the third transistor Q3 is N- among the transistors configured by the switching driving controller 10. It is desirable to configure the MOSFET as it can reduce the output ripple voltage.

The output terminal V _OUT may include an inductor, a capacitor, and a diode to smooth the voltage output from the third transistor Q13 to a DC voltage having a predetermined magnitude.

Looking at the operation of the present invention configured as described above are as follows.

When a high level signal is applied from the control IC 20, a high level signal is transferred to the gates of the first Q11 and the second transistor Q12 so that the first transistor Q11 is turned on. And the second transistor Q12 is turned OFF.

Accordingly, the third transistor Q13 is turned on by applying the reference voltage V _DD transmitted through the second transistor Q11 and outputs a voltage having a predetermined magnitude to the output terminal V _OUT .
That is, in the third transistor Q13, a channel is generated by the potential difference of the reference voltage V _DD applied to the gate, and a voltage having a predetermined magnitude of the reference voltage V _DD is drained through the generated channel. It is output to the output terminal V _OUT .

In addition, when a low level signal is applied from the control IC 20, a low level signal is applied to the gates of the first Q11 and the second transistor Q12 so that the first transistor Q11 is turned off. (OFF), the second transistor Q12 is turned on and the reference voltage V _DD is not applied to the third transistor Q13 so that the third transistor Q13 is turned off. do.
That is, when the second transistor Q12 is turned on, the third transistor Q13 applies the reference voltage V _DD to ground through a resistor. The reference voltage V _DD is not applied to the third transistor Q13 because the second transistor Q12 has a lower potential difference than the third transistor Q13.

Accordingly, the switch driving circuit according to the present invention prevents the generation of a current flowing through the third transistor Q13 from the reference voltage (V _DD ) to the ground when the circuit is turned on so that the third transistor Q13 is prevented. Is protected, and when a signal is input from the control IC 20, only one of the first (Q11) and the second transistor (Q12) is turned on so that the first (Q11) and the second ( Q12) The generation of constant current through the transistor at the same time is prevented.

As described above, the switching driving circuit according to the present invention has been described with reference to the illustrated drawings, but the present invention is not limited by the embodiments and drawings disclosed herein, and may be applied within the scope of the technical idea.

The switching driving circuit according to the present invention configured as described above includes a plurality of transistors to prevent the occurrence of overcurrent in the switching driving circuit to obtain a stable output voltage, and by reducing the size of the output ripple voltage, There is an effect that can improve the reliability of.

Claims (5)

The base is a pulse signal associated with the switching operation is input, the collector is a first transistor connected to the reference voltage; A second transistor having a base connected to the pulse signal, a collector connected to ground, and an emitter connected to an emitter of the first transistor; A third transistor whose gate is commonly connected to the emitter of the first transistor and the emitter of the second transistor, a source is connected to ground, and a drain is an output terminal; A switch driving control unit having a collector and a base of the first transistor and a resistor connected in common with the base of the second transistor; And an output terminal for removing and outputting noise included in a voltage output through the drain of the third transistor. The method of claim 1, The first transistor is an N-type type bipolar junction transistor (BJT), the second transistor is a P-type type bipolar junction transistor (BJT), and the third transistor is an N-channel field effect transistor. Switching drive circuit. delete delete delete

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