Voltage regulator and power supply

Patent metadata

Field	Value
Publication number	US-10936001-B2
Application number	US-202016780837-A
Country	US
Kind code	B2
Filing date	Feb 3, 2020
Priority date	Nov 28, 2017
Publication date	Mar 2, 2021
Grant date	Mar 2, 2021

Abstract

A voltage regulator and a power supply are provided. The voltage regulator includes an operational amplifier and an offset voltage control module. The offset voltage control module includes one or more stages of regulation branches connected in parallel, and controls an offset voltage of the operational amplifier with the one or more stages of regulation branches to regulate the output voltage. The offset voltage control module also includes a bandgap reference generation circuit, configured to generate a reference voltage irrelevant to a temperature coefficient that is received by the operational amplifier from the input terminal, wherein the bandgap reference generation circuit comprises at least one of: a ΔV GS -based bandgap reference generation circuit having a full CMOS reference offset structure, a PTAT unit-based and V GS -based bandgap reference generation circuit having a full CMOS reference offset structure, and a PTAT unit-based and BJT-based bandgap reference generation circuit having a complementary structure.

First claim

What is claimed is:

1. A voltage regulator, comprising:
an operational amplifier including an input terminal and an output terminal, and the operational amplifier is configured to generate an output voltage to be output from the output terminal based on a reference voltage received from the input terminal;
an offset voltage control module including one stage of regulation branch or more stages of regulation branches connected in parallel, and the offset voltage control module is configured to control an offset voltage of the operational amplifier with the one or more stages of regulation branches to regulate the output voltage; and
a bandgap reference generation circuit, configured to generate the reference voltage that is irrelevant to a temperature coefficient, wherein the bandgap reference generation circuit comprises at least one of: a AV GS -based bandgap reference generation circuit having a full CMOS reference offset structure, a PTAT unit-based and V GS -based bandgap reference generation circuit having a full CMOS reference offset structure, and a PTAT unit-based and BJT-based bandgap reference generation circuit having a complementary structure.

2. The voltage regulator according to claim 1 , wherein the regulation branch comprises a regulation element and a regulation switch, and the regulation branch is connected to a device affecting the offset voltage inside the operational amplifier; wherein conduction of the regulation branch is controlled by controlling conduction of the regulation switch, such that the regulation element of the conducted regulation branch is connected to the operational amplifier to control the offset voltage of the operational amplifier, and the regulation element is a MOS transistor.

3. The voltage regulator according to claim 2 , wherein the offset voltage control module comprises more stages of regulation branches, and width-to-length ratios of MOS transistors of different regulation branches are defined based on a predetermined rule to control a variation trend of the offset voltage.

4. The voltage regulator according to claim 3 , wherein the width-to-length ratios of the MOS transistors of the different regulation branches are defined in an ascending order based on a predetermined step to control the offset voltage to be subject to a linear variation.

5. The voltage regulator according to claim 2 , wherein when the regulation switches in all stages of regulation branches in the offset voltage control module are all turned off, the offset voltage is 0 V.

6. The voltage regulator according to claim 1 , wherein the operational amplifier comprises a differential input pair transistors; wherein at least one of the differential input pair transistors is connected in parallel to any one or more stages of regulation branches in the offset voltage control module to control a voltage difference between the differential input pair transistors by the any one or more stages of regulation branches in the offset voltage control module, and hence to control the offset voltage of the operational amplifier.

7. The voltage regulator according to claim 1 , wherein the bandgap reference generation circuit comprises at least one of the PTAT unit-based and V GS -based bandgap reference generation circuit having a full CMOS reference offset structure, and the PTAT unit-based and BJT-based bandgap reference generation circuit having a complementary structure.

8. The voltage regulator according to claim 7 , wherein the PTAT unit-based and BJT-based bandgap reference generation circuit having a complementary structure comprises:
a BJT transistor, configured to generate a voltage having a positive temperature coefficient based on a voltage between a base and an emitter of the BJT transistor; and
a MOS transistor-based PTAT unit, configured to generate a voltage having a negative temperature coefficient based on a MOS transistor operating in a subthreshold region;
wherein the emitter of the BJT transistor and the PTAT unit are connected to a drive voltage via a current unit, such that the BJT transistor and the PTAT unit have a predefined offset current such that the voltage having the positive temperature coefficient and the voltage having the negative temperature coefficient are complementary to each other and the reference voltage irrelevant to the temperature coefficient is generated.

9. The voltage regulator according to claim 8 , wherein the PTAT unit-based and BJT-based bandgap reference generation circuit having a complementary structure comprises: n groups of PTAT units and n BJT transistors, wherein the voltage having the positive temperature coefficient generated by each BJT transistor is complementary to the voltage having the negative temperature coefficient generated by each group of PTAT units, such that the generated reference voltage is an n-fold bandgap reference voltage.

10. The voltage regulator according to claim 9 , wherein the reference voltage is connected to a capacitive load.

11. The voltage regulator according to claim 9 , wherein when n is equal to 2, the PTAT unit-based and BJT-based bandgap reference generation circuit having a complementary structure comprises: BJT transistors B 1 and B 2 ; wherein an emitter of the BJT transistor B 1 is connected to the drive voltage via a current mirror, a base of the BJT transistor B 1 is connected to a collector thereof, and the collector is connected to the ground; an emitter of the BJT transistor B 2 is connected to the drive voltage via the current mirror, and an collector of the BJT transistor B 2 is connected to the ground, such that the voltage having the positive temperature coefficient is generated based on the voltage between the base and the emitter of the BJT transistor; and
two groups of MOS transistor-based PTAT units; wherein the two groups of PTAT units are arranged in series between the emitter of the BJT transistor B 1 and the base of the BJT transistor B 2 , a node between the two groups of PTAT units is a single-fold bandgap output node configured to output a single-fold bandgap reference voltage, and the emitter of the BJT transistor B 2 is a double-fold bandgap output node configured to output a double bandgap reference voltage.

12. The voltage regulator according to claim 11 , wherein an input node of the PTAT unit is connected to the output node of a previous stage of PTAT unit, and the output node of a PTAT unit is connected to the input node of a next stage of PTAT unit.

13. The voltage regulator according to claim 11 , wherein the PTAT unit includes two NMOS transistors MNA and MNB, and a source of MNA is connected to the ground, and a gate of MNA is connected to a gate of MNB and a drain of MNB, and the drain of MNB is connected to the drive voltage VDD via the current mirror.

14. The voltage regulator according to claim 8 , wherein the bandgap reference generation circuit further comprises a reference voltage control switch; wherein one terminal of the reference voltage control switch is connected to the drive voltage via the current unit, and the other terminal of the reference voltage control switch is connected to the PTAT unit to control a current flowing through the PTAT unit based on conduction and non-conduction of the reference voltage control switch, and hence to control a value of the reference voltage and a temperature coefficient of the reference voltage.

15. The voltage regulator according to claim 8 , wherein the current unit is a current mirror.

16. The voltage regulator according to claim 1 , further comprising a control switch, configured to be connected to the output terminal o

Assignees

• Shenzhen Goodix Tech Co Ltd

Inventors

• Du Wei
• Zhang Junjun

Classifications

• H03F3/45771

  using switching means · CPC title

• H03F3/45991

  by using balancing means · CPC title

• G05F1/575 Primary

  characterised by the feedback circuit · CPC title

• H03F3/45269

  Complementary non-cross coupled types · CPC title

• H03F2203/45101

  Control of the DC level being present · CPC title