IP Library Granted Patent US 8,144,485
Granted Patent B2
US 8,144,485 · App. 12/229,639 · Granted Mar 27, 2012

Direct current voltage conversion circuit

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Quick Facts
Patent No.
US 8,144,485
App. No.
12/229,639
Granted
Mar 27, 2012
Kind
B2
Abstract

A DC voltage conversion circuit ( 20 ) of the present disclosure includes a power supply ( 21 ), a first output ( 27 ), a second output ( 26 ), a transformer ( 22 ), a first voltage-regulating circuit ( 25 ), a second voltage regulating circuit ( 24 ), and a step-up DC-DC converter ( 23 ). The first voltage-regulating circuit includes a transistor ( 254 ) having drain and source electrodes, a first capacitor ( 252 ) connected between ground and the first output, and a first diode ( 251 ). The first output is connected to ground via the anode and cathode of the first diode, the transformer, and the drain and source electrodes of the transistor in series. The power supply is configured to provide a second voltage to the second output via the transformer and the second voltage-regulating circuit in series. The step-up DC-DC converter is configured to regulate voltages of the first and second outputs according to feedback voltages from the first and second outputs.

Claims (42)

1. A direct current voltage conversion circuit comprising:

a power supply;

a first output;

a second output;

a transformer comprising a primary coil and a secondary coil;

a first voltage-regulating circuit comprising:

a transistor including a drain electrode and a source electrode;

a first capacitor connected between ground and the first output; and a first diode, having an anode and a cathode, wherein the first output is capable of being connected to ground via the anode and cathode of the first diode, the transformer, and the drain and source electrodes of the transistor in series;

a second voltage-regulating circuit, wherein the power supply is configured to provide a second voltage to the second output via the transformer and the second voltage-regulating circuit in series, the second voltage-regulating circuit comprises a second diode, the primary coil of the transformer and the second diode is connected in series between the power supply and the second output; and

a step-up DC-DC converter configured to receive a first feedback voltage from the first output and regulate a first voltage of the first output by turning on or turning off the transistor according to the first feedback voltage, and further configured to receive a second feedback voltage from the second output and regulate the second voltage of the second output according to the second feedback voltage.

2. The direct current voltage conversion circuit in claim 1 , wherein the second voltage-regulating circuit further comprises a second capacitor, the second capacitor being connected between ground and the second output, and the power supply being connected to the second output via the transformer, the anode of the second diode, and the cathode of the second diode in series.

3. The direct current voltage conversion circuit in claim 2 , wherein the first output is connected to ground via the anode of the first diode, the cathode of the first diode, the secondary coil, the drain electrode of the transistor, and the source electrode of the transistor in series.

4. The direct current voltage conversion circuit in claim 3 , wherein the step-up DC-DC converter comprises a first control output, a second control output, a first feedback terminal, and a second feedback terminal, the first control output being connected to the anode of the second diode, the second control output being connected to a gate electrode of the transistor, the first feedback terminal being configured to receive the first feedback voltage from the first output, and the second feedback terminal being configured to receive the second feedback voltage from the second output.

5. The direct current voltage conversion circuit in claim 4 , further comprising a first feedback branch circuit, the first feedback branch circuit being connected between ground and the first output and comprising a first resistor and a second resistor connected in series, the first feedback terminal receiving the first feedback voltage from the first output via the first resistor.

6. The direct current voltage conversion circuit in claim 5 , further comprising a second feedback branch circuit, the second feedback branch circuit being connected between ground and the second output and comprising a third resistor and a fourth resistor connected in series, the second feedback terminal receiving the second feedback voltage from the second output via the third resistor.

7. The direct current voltage conversion circuit in claim 6 , further comprising a third capacitor and a fourth capacitor, the third capacitor being connected between ground and the first output and configured to filter noise interference of the first voltage of the first output, the fourth capacitor being connected between ground and the second output and configured to filter noise interference of the second voltage of the second output.

8. The direct current voltage conversion circuit in claim 2 , wherein the power supply is a 1.5 volt direct current power supply.

9. The direct current voltage conversion circuit in claim 8 , wherein the first voltage is equal to −8 volts, and the second voltage is equal to 3.3 volts.

10. A direct current voltage conversion circuit comprising:

a power supply;

a first output;

a second output;

a transformer comprising a primary coil and a secondary coil;

a first voltage-regulating circuit comprising:

a transistor including a gate electrode, a drain electrode and a source electrode;

a first capacitor connected between ground and the first output; and

a first diode, having an anode and a cathode, the first output being connected to ground via the anode and cathode of the first diode, the transformer, and the drain and source electrodes of the transistor in series;

a second voltage-regulating circuit, the power supply configured to provide a second voltage to the second output via the transformer and the second voltage-regulating circuit in series, the second voltage-regulating circuit comprising a second diode, the primary coil of the transformer and the second diode being connected in series between the power supply and the second output; and

a step-up DC-DC converter comprising: a first feedback terminal connected to the first output; a second feedback terminal connected to the second output; a first control output connected to the gate electrode of the transistor; and a second control output connected to the second voltage-regulating circuit.

11. The direct current voltage conversion circuit in claim 10 , wherein the first output is connected to ground via the anode and cathode of the first diode, the secondary coil, and the drain and source electrodes of the transistor in series.

12. The direct current voltage conversion circuit in claim 10 , wherein the power supply is a 1.5 volt power supply.

13. The direct current voltage conversion circuit in claim 12 , wherein a voltage of the first output is equal to −8 volts, and a voltage of the second output is equal to 3.3 volt.

14. The direct current voltage conversion circuit in claim 3 , wherein the secondary coil of the transformer is connected between the anode of the first diode and the drain electrode of the transistor, and the source electrode of the transistor is grounded.

15. The direct current voltage conversion circuit in claim 14 , wherein the first capacitor is connected between the source electrode of the transistor and the first output.

16. The direct current voltage conversion circuit in claim 11 , wherein the secondary coil of the transformer is connected between the anode of the first diode and the drain electrode of the transistor, and the source electrode of the transistor is grounded.

17. The direct current voltage conversion circuit in claim 15 , wherein the first capacitor is connected between the source electrode of the transistor and the first output.

18. An apparatus, comprising:

a transformer comprising a primary coil and a secondary coil, the primary coil comprising two ends;

a first voltage-regulating circuit comprising a first diode, a first capacitor and a transistor cooperatively converting a positive power voltage received by the transformer to a negative output voltage, wherein a source electrode of the transistor is grounded, a drain electrode of the transistor is connected to a cathode of the first diode via the secondary coil of the transformer, an anode of the first diode is connected to a first output, and is grounded via the first capacitor;

a second voltage-regulating circuit comprising a second diode and a second capacitor cooperatively converting the positive power voltage received by the transformer to a positive output voltage, wherein an anode of the second diode is connected to one end of the primary coil of the transformer, the other end of the primary coil is configured to receive a DC voltage, and a cathode of the second diode is connected to a second output, and is grounded via the second capacitor.

19. The apparatus of claim 18 , wherein a gate electrode of the transistor is configured to receive a control signal from a single-chip DC-DC converter, the single-chip DC-DC converter provides the control signal to switch on or switch off the transistor in accordance with a first feedback signal fed back from the first output, and provide a pulse signal with a duty ratio corresponding to a second feedback signal fed back from the second output.

20. The apparatus of claim 19 , wherein the single-chip DC-DC converter is a step-up DC-DC converter enabling each of the negative output voltage and the positive output voltage to have an amplitude greater than the positive power voltage received by the transformer.

Assignments (1)
CHANGE OF NAME Recorded Apr 7, 2014
From: CHIMEI INNOLUX CORPORATION
To: INNOLUX CORPORATION
Reel/Frame 032621/0718 →