VOLTAGE CONVERSION CIRCUIT AND CHARGING DEVICE EMPLOYING THE SAME

• US 20120139478A1
• Filed: 01/21/2011
• Published: 06/07/2012
• Est. Priority Date: 12/03/2010
• Status: Active Grant

• Current Assignee: Chi Mei Communication Systems Incorporated (Hon Hai Precision Industry Co., Ltd.), Shenzhen Futaihong Precision Industry Company Limited (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Chi Mei Communication Systems Incorporated (Hon Hai Precision Industry Co., Ltd.), Shenzhen Futaihong Precision Industry Company Limited (Hon Hai Precision Industry Co., Ltd.)
• Inventors: WU, HAI-ZHOU
• Granted Patent: US 8,742,731 B2
• Time in Patent Office: Days
• US Class Current: 320/107
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

Abstract

A voltage conversion circuit for a charging device includes a voltage-stabilizing circuit and a switching circuit. The voltage-stabilizing circuit includes a voltage stabilizer circuit and a feedback resistor, the voltage stabilizer circuit comprises an input pin, an output pin, and a feedback pin. The switching circuit includes a switch and at least two divider resistors, the switch comprises at least two data input terminals, a data output terminal, and two control terminals. The input pin is connected to a power source, and the feedback resistor is connected between the feedback pin and ground. The data input terminals are respectively connected to the output pin through one of the divider resistors, the data output terminal is connected between the feedback pin and the feedback resistor, the two control terminals are capable of receiving control signals to control the data output terminal to selectively connect to one of the data input terminals.

Claims

1. A voltage conversion circuit, comprising:

a voltage-stabilizing circuit including a voltage stabilizer circuit and a feedback resistor, the voltage stabilizer circuit comprising an input pin, an output pin, and a feedback pin; and

a switching circuit including a switch and at least two divider resistors, the switch comprising at least two data input terminals, a data output terminal, and two control terminals;

wherein the input pin is connected to a power source, and the feedback resistor is connected between the feedback pin and ground, the data input terminals are respectively connected to the output pin through one of the divider resistors, the data output terminal is connected between the feedback pin and the feedback resistor, the two control terminals are capable of receiving control signals to control the data output terminal to selectively connect to one of the data input terminals.

2. The voltage conversion circuit as claimed in claim 1, wherein the output terminal is capable of feeding a feedback voltage back to the feedback pin.

3. The voltage conversion circuit as claimed in claim 2, wherein the output pin is operable to output steady current by adjusting the feedback voltage.

4. The voltage conversion circuit as claimed in claim 1, wherein the voltage-stabilizing circuit further includes a capacitor, the voltage stabilizer circuit comprises a soft start pin, the capacitor is connected between the soft start pin and ground to produce a soft-start delay function.

5. The voltage conversion circuit as claimed in claim 1, wherein the voltage-stabilizing circuit further includes a timing resistor, the voltage stabilizer circuit comprises a timing pin, the timing resistor is connected between the timing pin and the input pin.

6. The voltage conversion circuit as claimed in claim 1, wherein the voltage stabilizer circuit further includes an enable pin, the enable pin is connected to the power source to get power to function the voltage stabilizer circuit.

7. The voltage conversion circuit as claimed in claim 1, wherein the switch is a single-pole triple-throw analog switch.

8. A charging device for charging a battery of an electronic device by a USB interface of the electronic device, comprising:

a charging circuit connected to the battery;

a voltage conversion circuit including a voltage-stabilizing circuit and a switching circuit; and

a control module;

wherein the voltage-stabilizing circuit receives current from the USB interface, the switching circuit includes a switch and at least two divider resistors, the switch is connected to the voltage-stabilizing circuit through one of the divider resistors, the control module is connected to the switch and capable of controlling a data output terminal of the switch to connect to one of the divider resistors according to real-time voltage of the battery, and the data output terminal is capable of feeding voltage signals back to the voltage-stabilizing circuit so that the voltage-stabilizing circuit can output steady current to the charging circuit.

9. The charging device as claimed in claim 8, wherein the voltage-stabilizing circuit includes a voltage stabilizer circuit and a feedback resistor, the voltage stabilizer circuit includes a feedback pin, the feedback resistor is connected between the feedback pin and ground, and the data output terminal is connected between the feedback pin and ground.

10. The charging device as claimed in claim 8, wherein the voltage-stabilizing circuit includes a voltage stabilizer circuit, the stabilizer circuit includes an output pin, the switch includes at least two data input terminals, each data input terminal is connected to the output pin through one of the divider resistor.

11. The charging device as claimed in claim 10, wherein the switch includes two control terminals, the two control terminals are connected to the control module to control the data output terminal to connect to one of the data input terminals.

12. The charging device as claimed in claim 10, wherein the charging circuit is connected to the output pin of the voltage stabilizer circuit.

13. The charging device as claimed in claim 8, wherein the control module includes a ADC module, a operation module, and two GPIO interfaces, the ADC module is connected to the batter to convert the real-time voltage of the battery into digital signals, the operation module is connected to the ADC module to control the two GPIO interfaces to trigger on logic signals according to the digital signals.

14. The charging device as claimed in claim 13, wherein the switch include two control terminals, the two control terminals are respectively connected to the two GPIO interfaces for controlling the data output terminal of the switch.

15. The charging device as claimed in claim 8, wherein the charging device further includes an over voltage protection circuit, the over voltage protection circuit is connected between the USB interface and the voltage conversion circuit.

16. The charging device as claimed in claim 8, wherein the switch is a single-pole triple-throw analog switch.