Voltage regulator

• US 6,150,798 A
• Filed: 09/02/1998
• Issued: 11/21/2000
• Est. Priority Date: 09/18/1997
• Status: Expired due to Fees

• Current Assignee: STMicroelectronics SA (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SA (STMicroelectronics NV)
• Inventors: Serra, Carlos, Ferry, Claude
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): Patel, Rajnikant B.
• Application Number:
  US09/146,004
• Time in Patent Office: 811 Days
• Field of Search: 323/273, 323/284, 323/285, 323/282, 323/224, 323/288, 323/266, 363/26, 363/23, 363/124
• US Class Current: 323/273
• CPC Class Codes: G05F 1/56 using semiconductor devices in series with the load as final control devices G05F1/461 takes precedence
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02M 1/0045 Converters combining the concepts of switch-mode regulation and linear regulation, e.g. linear pre-regulator to switching converter, linear and switching converter in parallel, same converter or same transistor operating either in linear or switching mode
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load

Abstract

The present invention relates to a voltage regulator of a voltage meant to supply a load from a battery, including a first switched-mode power supply type voltage regulation component, a second linear regulator type voltage regulation component, and a control circuit that selects one of the two regulation components according to the voltage difference between the battery voltage and the output voltage.

Claims

1. A voltage regulator meant to supply a load from a battery, including:

a first switched-mode power supply type voltage regulation component;

a second linear regulator type voltage regulation component;

a control means for selecting one of the two regulation components according to the voltage difference between the battery voltage and the output voltage;

wherein the linear regulation component is selected when the voltage difference is lower than a first predetermined threshold value;

wherein the switched-mode power supply component is selected when the current consumed by the load is higher than a second predetermined threshold value; and

wherein the switched-mode power supply component is selected when both the voltage difference is higher than the first threshold value and the current consumed by the load is higher than the second threshold value.

2. The voltage regulator of claim 1, wherein the switched-mode power supply component is selected when the current consumed by the load is higher than a second predetermined threshold value.

3. The voltage regulator of claim 1, including:

two MOS transistors connected in series between two terminals that receive the battery voltage;

a pulsewidth modulation control circuit that controls the transistors;

a linear control circuit that controls the first transistor; and

a selection circuit that selects the control circuit.

4. The voltage regulator of claim 3, wherein respective output signals of the control circuits, sent onto the gate of the first MOS transistor, are provided by tri-state amplifiers.

5. The voltage regulator of claim 3, wherein the voltage regulator includes an unregulated operating mode, in which the first transistor is saturated.

6. The voltage regulator of claim 1, meant to supply a mobile phone, and including a terminal that can receive a signal indicative of the stand-by state of the mobile phone.

12. The voltage regulator of claim 1, adapted to supply a mobile phone, and including a terminal that can receive a signal indicative of the stand-by state of the mobile phone.

7. A voltage regulator adapted to supply a load from a battery, comprising:

a first switched-mode power supply type voltage regulation component;

a second linear regulator type voltage regulation component; and

a control circuit that selects one of the two regulation components according to the voltage difference between the battery voltage and the output voltage;

wherein the linear regulation component is selected when the voltage difference is lower than a first predetermined threshold value;

wherein the switched-mode power supply component is selected when the current consumed by the load is higher than a second predetermined threshold value; and

wherein the switched-mode power supply component is selected when both the voltage difference is higher than the first threshold value and the current consumed by the load is higher than the second threshold value.

8. The voltage regulator of claim 7, wherein the control circuit selects one of the regulation components according to the current consumed by the load.

9. The voltage regulator of claim 7, including:

two MOS transistors connected in series between two terminals that receive the battery voltage;

a pulsewidth modulation control circuit that controls the transistors;

a linear control circuit that controls the first transistor; and

a selection circuit that selects the control circuit.

10. The voltage regulator of claim 9, wherein respective output signals of the control circuits, sent onto the gate of the first MOS transistor, are provided by tri-state amplifiers.

11. The voltage regulator of claim 9, wherein the voltage regulator includes an unregulated operating mode, in which the first transistor is saturated.

13. A method of supplying a load from a battery, comprising the steps of:

selecting a linear regulator type voltage regulation when a voltage difference between a battery voltage and an output voltage is lower than a first predetermined threshold value;

selecting switched-mode type voltage regulation when a current consumed by the load is higher than a second predetermined threshold value; and

selecting switched-mode type voltage regulation when both the voltage difference is higher than the first threshold value and the current consumed by the load is higher than the second threshold value.