Linearly regulated power supply

• US 20060076938A1
• Filed: 10/13/2005
• Published: 04/13/2006
• Est. Priority Date: 10/13/2004
• Status: Abandoned Application

• Current Assignee: Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: Jiang, Wu
• Application Number:
  US11/250,130
• Publication Number:
  US 20060076938A1
• Time in Patent Office: Days
• US Class Current: 323/272
• CPC Class Codes: G05F 1/56 using semiconductor devices in series with the load as final control devices G05F1/461 takes precedence

Abstract

A linearly regulated power supply is provided for providing a regulated load voltage to a load. In a preferred embodiment, the linearly regulated power supply includes: a voltage reference circuit for providing a first voltage reference; a resistive voltage divider connected to the voltage reference circuit for receiving the first voltage reference and then providing a second voltage reference; an error amplifier for receiving the second voltage reference and providing a controlling voltage; and a regulating circuit controlled by the controlling voltage, the regulating circuit receiving a source voltage and then providing a load voltage to a load, the regulating circuit including two transistors connected to each other in parallel for regulating the load voltage. The linearly regulated power supply is capable of providing a greater current to the load and the components of the linearly regulated power supply can be used efficiently.

Claims

1. A linearly regulated power supply comprising:

a voltage reference circuit for providing a first voltage reference;

a resistive voltage divider connected to the voltage reference circuit for receiving the first voltage reference and then providing a second voltage reference;

an error amplifier for receiving the second voltage reference and providing a controlling voltage; and

a regulating circuit controlled by the controlling voltage, the regulating circuit receiving a source voltage and then providing a load voltage to a load, the regulating circuit including two transistors connected to each other in parallel for regulating the load voltage.

2. The linearly regulated power supply as claimed in claim 1, wherein the resistive voltage divider comprises two resistors connected to each other in series, and a node between the resistors for providing the second voltage reference to the error amplifier.

3. The linearly regulated power supply as claimed in claim 1, wherein the error amplifier includes a non-inverting input terminal connected to the resistive voltage divider for receiving the second voltage reference, an inverting input terminal connected to the load for sensing the load voltage, and an output terminal connected to the regulating circuit for controlling the regulating circuit.

4. The linearly regulated power supply as claimed in claim 3, wherein the transistors are N-channel MOSFETs (metal-oxide-semiconductor field-effect transistors).

5. The linearly regulated power supply as claimed in claim 4, wherein the regulating circuit has a gate terminal connected to gates of the transistors, a source terminal connected to sources of the transistors, and a drain terminal connected to drains of the transistors.

6. The linearly regulated power supply as claimed in claim 5, wherein the drain terminal of the regulating circuit receives the source voltage, and the source terminal of the regulating circuit is connected to the load for providing the load voltage regulated by the regulating circuit.

7. The linearly regulated power supply as claimed in claim 1, wherein the error amplifier includes an inverting input terminal connected to the resistive voltage divider for receiving the second voltage reference, a non-inverting input terminal connected to the load for sensing the load voltage, and an output terminal connected to the regulating circuit for controlling the regulating circuit.

8. The linearly regulated power supply as claimed in claim 7, wherein the transistors are P-channel MOSFETs (metal-oxide-semiconductor field-effect transistors).

9. The linearly regulated power supply as claimed in claim 8, wherein the regulating circuit has a gate terminal connected to gates of the transistors, a source terminal connected to sources of the transistors, and a drain terminal connected to drains of the transistors.

10. The linearly regulated power supply as claimed in claim 9, wherein the source terminal of the regulating circuit receives the source voltage, and the drain terminal of the regulating circuit is connected to the load for providing the load voltage regulated by the regulating circuit.

11. A linearly regulated power supply comprising:

a reference circuit for providing a voltage reference;

an error amplifier for receiving the voltage reference and providing a controlling voltage; and

a regulating circuit controlled by the controlling voltage, the regulating circuit receiving a source voltage and then providing a regulated load voltage to a load, the regulating circuit including two transistors connected to each other in parallel for regulating the load voltage.

12. The linearly regulated power supply as claimed in claim 11, wherein the error amplifier includes a first input terminal connected to the reference circuit for receiving the voltage reference, a second input terminal connected to the load for sensing the load voltage, and an output terminal connected to the regulating circuit for controlling the regulating circuit.

13. The linearly regulated power supply as claimed in claim 11, wherein the regulating circuit has a gate terminal connected to gates of the transistors, a source terminal connected to sources of the transistors, and a drain terminal connected to drains of the transistors.

14. The linearly regulated power supply as claimed in claim 13, wherein the transistors are N-channel MOSFETs (metal-oxide-semiconductor field-effect transistors), the drain terminal of the regulating circuit receives a source voltage, and the source terminal of the regulating circuit is connected to the load for providing the load voltage regulated by the regulating circuit.

15. The linearly regulated power supply as claimed in claim 13, wherein the transistors are P-channel MOSFETs (metal-oxide-semiconductor field-effect transistors), the source terminal of the regulating circuit receives a source voltage, and the drain terminal of the regulating circuit is connected to the load for providing the load voltage regulated by the regulating circuit.

16. A method to regulate a power supply, comprising the steps of:

providing a voltage reference as a source of a power supply;

installing at least two regulating means in a regulating circuit so as to have said at least two regulating means accepting a same input of said regulating circuit and providing contributorily a same output of said regulating circuit;

electrically connecting said regulating circuit with an electrical load capable of using power of said power supply so as to provide said output of said regulating circuit to said load; and

electrically connecting a voltage stabilizer between said voltage reference and said regulating device so that said voltage stabilizer accepts said voltage reference and said output of said regulating circuit, and generates said input into said regulating circuit.

17. The method as claimed in claim 16, wherein said at least two regulating means of said regulating circuit are two parallel-connected transistors including metal-oxide semiconductor field-effect transistors (MOSFET).

18. The method as claimed in claim 16, further comprising the step of electrically connecting said at least two regulating means of said regulating circuit with a same source voltage in order to provide said output of said regulating circuit.

19. The method as claimed in claim 16, wherein said voltage stabilizer is an error amplifier.