JP2006345659A - External connection circuit of dual output dc/dc converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and inexpensive external connection circuit using one dual output DC/DC converter for acquiring two different voltage outputs. <P>SOLUTION: In the dual output DC/DC converter 1, an output voltage controlling circuit 4 and an inductance 5 are mounted between an input lines 2 and an output line 3, the ground GND and a diode D1 are mounted and connected between the output voltage controlling circuit and the inductance, an output voltage controlling circuit 7 and an inductance 8 are mounted between the output lines 3, 6, the ground GND and a diode D2 are mounted and connected between the output voltage controlling circuit and the inductance, a capacitor C1 is mounted between the ground and an external output line Vout1 connected to the output line 3, a capacitor C2 is mounted between the ground and an external output line Vout2 connected to the output line 6, and a capacitor C3 is mounted between the ground and an external input line Vin connected to the input line 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an external connection circuit of a two-output DC / DC converter. More specifically, the DC / DC converter is provided with a first output line and a second output line, and the external connection circuit includes a capacitor. Thus, the present invention relates to an external connection circuit of a two-output DC / DC converter that can obtain two currents having different voltages from one DC / DC converter.

  In general, the DC / DC converter for obtaining these two currents is provided with a DC / DC converter depending on the output, which is an obstacle to miniaturization.

Conventionally, for example, without using a Schottky barrier diode, the switching circuit is composed of an FET, a transistor, and a resistor, and when the output voltage of the AC adapter falls below a set voltage, the FET is turned on and the AC adapter input is switched to the battery input. (Refer to Patent Document 1), a voltage supplied from a voltage supply circuit 2 by a resistance division method is input to one side, a reference voltage is input to the other side, and an output voltage from the comparator 3 is input to the other side. Is input to the other and the output from the oscillation circuit 13 is input to the NAND circuit 14, and the output of the NAND circuit 14 is input to the gate of the N-channel MOS transistor 7 via the inverter 15. In the converter, the constant signal “H” provided to the NAND circuit 14 is supplied within a certain period immediately after the power is turned on. The auxiliary circuit 20 that intervenes between the comparator 3 and the NAND circuit 14 (see Patent Document 2), or the switch 20 on the transformer 30 that insulates the drive signal supplied from the voltage control unit 611 to the semiconductor switch 2. , 8 are provided to generate voltage for turning on, and at the time of step-down operation, the relay contacts 91 and 92 are closed to energize the transformer 30, and the switch 2 is turned on and off. A device is disclosed in which the relay contacts 91 and 92 are opened during energization and the transformer 30 is energized to turn on the switches 20 and 8 and the switch 3 is intermittently turned on (see Patent Document 3).
JP-A-9-182288 JP 2000-134913 A JP 2004-135478 A

  However, the conventionally disclosed one does not have a two-output DC / DC converter, and two DC / DC converters are required for the two outputs, and the miniaturization cannot be achieved.

  In view of the foregoing problems, as a result of diligent research, the two-output DC / DC converter has a first output voltage control circuit and a first inductance interposed between the first output line and the first output. A connection point between the voltage control circuit and the first inductance and the ground are connected via a first diode, and a second output is provided between the first output line and the second output line. The voltage control circuit and the second inductance are interposed, the connection point between the second output voltage control circuit and the second inductance and the ground are connected via the second diode, and the first A first capacitor is interposed between the first external output line connected to the output line and the ground, and a second capacitor is connected between the second external output line connected to the second output line and the ground. Insert a capacitor between the external input line connected to the input line and the ground. Capacitor is obtained by interposed.

  An external connection circuit of a two-output DC / DC converter according to the present invention is provided with an input line, a first output line, and a second output line in the two-output DC / DC converter, and a first output voltage control circuit and a second output circuit. The output voltage control circuit of each is provided, and each external connection circuit is provided with a capacitor, so that an output having two voltages different from each other can be obtained by one two-output DC / DC converter. It is an innovative and highly practical invention that can be provided at low cost.

  The present invention relates to an external connection circuit of a two-output DC / DC converter, and more specifically, a two-output DC / DC converter 1 is provided with a first output line 3 and a second output line 6, and an external connection circuit. Respectively, capacitors C1. C2. The present invention relates to an external connection circuit of a two-output DC / DC converter that can obtain two different currents of two voltages by one two-output DC / DC converter 1 by providing C3. 1 includes a first output voltage control circuit 4 and a first inductance 5 interposed between an input line 2 and a first output line 3, and the first output voltage control circuit 4 and the first output line 3. The connection point between the first output line 3 and the second output line 6 is connected to the connection point between the first output line 3 and the ground GND via the first diode D1. A voltage control circuit 7 and a second inductance 8 are interposed, and a connection point between the second output voltage control circuit 7 and the second inductance 8 and the ground GND are connected via a second diode D2. Connecting the first and second A first capacitor C1 is interposed between the first external output line Vout1 connected to the force line 3 and the ground GND, and the second external output line Vout2 connected to the second output line 6 and the A second capacitor C2 is interposed between the ground GND and a third capacitor C3 is interposed between the external input line Vin connected to the input line 2 and the ground GND. is there.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings of an embodiment of an external connection circuit of a DC / DC converter of the present invention, FIG. 1 is a circuit diagram of an embodiment of an external connection circuit of a 2-output DC / DC converter of the present invention. .

  That is, in the embodiment of the external connection circuit of the two-output DC / DC converter of the present invention, as shown in FIG. 1, the two-output DC / DC converter 1 has one input line 2 and two DC outputs with different voltages. It has two output lines 3.6 for

  The first output voltage control circuit 4 is interposed between the input line 2 and the first output line 3 together with the first inductance 5, and the first output voltage control circuit 4 is the first output voltage control circuit 4. Are connected via a transistor (MOSFET) 4a.

  Next, the first diode D1 has a cathode connected to provide a connection point between the first output voltage control circuit 4 and the first inductance 5, and an anode connected to the ground GND. .

  Next, the first resistor R1 and the second resistor R2 are connected, one side is connected to the output side of the first inductance 5, the other side is connected to the ground GND, and the first resistor R1 and the second resistor R2 are connected. A connection point is provided between the resistor R2 and connected to the first output voltage control circuit 4.

  Further, the second output voltage control circuit 7 is interposed between the first output line 3 and the second output line 6 together with the second inductance 8, and the second output voltage control circuit 7. Are connected via a second transistor (MOSFET) 7a.

  Further, the second diode D2 has a cathode connected to provide a connection point between the second output voltage control circuit 7 and the second inductance 8, and an anode connected to the ground GND. is there.

  Next, the third resistor R3 and the fourth resistor R4 are connected, one side is connected to the output side of the second inductance 8, the other side is connected to the ground GND, and the third resistor R3 and the fourth resistor R4 are connected. A connection point is provided between the resistors R4 and connected to the second output voltage control circuit 7.

  The first capacitor C1 is interposed between the first external output line Vout1 connected to the first output line 3 and the ground GND, and the first external output line Vout1 has 11 Although a DC output voltage of 0.7 to 12.3 V is output, in the embodiment, a DC output voltage of 12 V is output.

  Further, the second capacitor C2 is interposed between the second external output line Vout2 connected to the second output line 6 and the ground GND. A DC output voltage of .85 to 5.15 V is output, but in the embodiment, a DC output voltage of 5 V is output.

  Further, the third capacitor C3 is interposed between the external input line Vin connected to the input line 2 and the ground GDN, and the DC input voltage from the external input line Vin is 16 to 40V. In the embodiment, a current of a DC input voltage of 32V is input.

  The external connection circuit of the two-output DC / DC converter of the present invention is used for a gaming machine or the like. The DC input voltage of 16 to 40V of one DC / DC converter is changed to the DC output voltage of 11.7 to 12.3V. It converts to a DC output voltage of 4.85 to 5.15 V, and is ideal for overcurrent protection and overheat protection as a protection circuit while reducing the size.

FIG. 1 is a circuit diagram of an embodiment of an external connection circuit of a DC / DC converter according to the present invention.

Explanation of symbols

1 2 output DC / DC converter 2 input line 3 first output line 4 first output voltage control circuit 4a second transistor (MOSFET)
5 1st inductance 6 2nd output line 7 2nd output voltage control circuit 7a 2nd transistor (MOSFET)
8 Second inductance GND Ground D1 First diode D2 Second diode C1 First capacitor C2 Second capacitor C3 Third capacitor R1 First resistor R2 Second resistor R3 Third resistor R4 Fourth Resistance Vout1 First external output line Vout2 Second external output line Vin External input line

Claims (1)

The two-output DC / DC converter includes a first output voltage control circuit and a first inductance interposed between an input line and a first output line, and the first output voltage control circuit and the first output line A connection point between the first output line and the ground line is interposed between the first output line and the second output line. A second inductance is interposed, a connection point between the second output voltage control circuit and the second inductance and a ground line are connected via a second diode, and the first inductance is connected. A second capacitor is connected between the first external output line connected to the output line and the external ground line connected to the ground line, and connected to the second output line. And a second capacitor between the ground line and the external ground line connected to the ground line. And a third capacitor interposed between the external input line connected to the input line and the external ground line connected to the ground line. circuit.

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