# US 2019/0318790 A1 · Circuit for regulating leakage current in charge pump

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- Number: US 2019/0318790 A1
- Document ID: US20190318790A1
- Status: Published application
- Kind: A1
- Application number: 16/226,168
- Filed: 2018-12-19
- Published: 2019-10-17
- Earliest claimed: 2018-04-12
- Assignees: Wuhan Xinxin Semiconductor Manufacturing Co., Ltd.
- Applicants: Wuhan Xinxin Semiconductor Manufacturing Co., Ltd.
- Inventors: Yuan TANG; Bin SHENG; Byoung Kwon CHA; Yi XU; Jen-Tai HSU
- Web page: https://patentgrep.com/patent/US20190318790A1

## CPC

- G05F 3/02: Regulating voltage or current
- G05F 3/205: {Substrate bias-voltage generators (for static stores G11C5/146)}
- G11C 5/145: {Applications of charge pumps; Boosted voltage circuits; Clamp circuits therefor (G11C5/141 takes precedence)}
- G11C 16/14: Circuits for erasing electrically, e.g. erase voltage switching circuits
- G11C 16/30: Power supply circuits
- H02M 3/07: using capacitors charged and discharged alternately by semiconductor devices with control electrode {, e.g. charge pumps}
- G05F: SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
- G11C: STATIC STORES (semiconductor memory devices H10B)
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)

## Abstract

A circuit for regulating a leakage current in a charge pump is disclosed. The circuit includes a bias voltage generating circuit and a first transistor, wherein: the bias voltage generating circuit generates a bias voltage that is proportional to a supply voltage; a gate of the first transistor is coupled to the bias voltage; the first transistor has a drain that is coupled to an output of the charge pump and a source that is grounded; a voltage the drain of the first transistor is proportional to the supply voltage; and a current flowing through the source and drain of the first transistor is proportional to the supply voltage that powers the charge pump.

## Claims

### Claim 1

A circuit for regulating a leakage current in a charge pump, comprising a bias voltage generating circuit and a first transistor, wherein:
the bias voltage generating circuit generates a bias voltage that is proportional to a supply voltage;
the first transistor has a gate coupled to the bias voltage and a source that is grounded;
the first transistor has a drain coupled to an output of the charge pump, a voltage at the drain of the first transistor being proportional to the supply voltage; and
a current between the source and drain of the first transistor is proportional to the supply voltage that powers the charge pump.

### Claim 2 (depends on 1)

The circuit of claim 1, wherein the first transistor is an N-channel field-effect transistor.

### Claim 3 (depends on 1)

The circuit of claim 1, further comprising a second transistor,
the second transistor having a gate coupled to the supply voltage, a source connected to the drain of the first transistor and a drain connected to the output of the charge pump.

### Claim 4 (depends on 3)

The circuit of claim 3, wherein the second transistor is an N-channel field-effect transistor.

### Claim 5 (depends on 3)

The circuit of claim 3, wherein a breakdown voltage between the source and drain of the second transistor is higher than a breakdown voltage between the source and drain of the first transistor.

### Claim 6 (depends on 1)

The circuit of claim 1, wherein the bias voltage generating circuit comprises a third transistor and a fourth transistor, wherein:
the third transistor has a gate that is grounded, a source coupled to the supply voltage and a drain connected to a drain of the fourth transistor; and
the fourth transistor has a gate connected both to the drain of the fourth transistor and the gate of the first transistor and a source that is grounded.

### Claim 7 (depends on 6)

The circuit of claim 6, wherein the third transistor is a P-channel field-effect transistor and the fourth transistor is an N-channel field-effect transistor.

### Claim 8 (depends on 6)

The circuit of claim 6, wherein the gate of the first transistor is connected to the drains of the third and fourth transistors.

### Claim 9 (depends on 1)

The circuit of claim 1, wherein the voltage at the drain of the first transistor is equal to the supply voltage minus a threshold voltage of the first transistor.

### Claim 10 (depends on 1)

The circuit of claim 1, wherein the supply voltage ranges from 1.6 V to 3.9 V.

### Claim 11 (depends on 1)

The circuit of claim 1, wherein a current flowing through the source and drain of the first transistor ranges from 10 μA to 70 μA.

### Claim 12

A circuit for regulating a leakage current in a charge pump, comprising a first transistor, a third transistor and a fourth transistor, wherein:
the first transistor has a gate connected to drains of the third and fourth transistors for receiving a bias voltage that is proportional to a supply voltage;
the first transistor has a drain coupled to an output of the charge pump and a source that is grounded, a voltage at the drain of the first transistor being proportional to the supply voltage; the third transistor has a gate that is grounded, a source coupled to the supply voltage and the drain connected to the drain of the fourth transistor;
the fourth transistor has a gate connected both to the drain of the fourth transistor and the gate of the first transistor and a source that is grounded; and
a current between the source and drain of the first transistor is proportional to the supply voltage that powers the charge pump.

### Claim 13 (depends on 12)

The circuit of claim 12, wherein the first transistor is an N-channel field-effect transistor, the third transistor is a P-channel field-effect transistor and the fourth transistor is an N-channel field-effect transistor.

### Claim 14 (depends on 12)

The circuit of claim 12, further comprising a second transistor,
the second transistor having a gate coupled to the supply voltage, a source connected to the drain of the first transistor and a drain connected to the output of the charge pump.

### Claim 15 (depends on 14)

The circuit of claim 14, wherein the second transistor is an N-channel field-effect transistor.

### Claim 16 (depends on 14)

The circuit of claim 14, wherein a breakdown voltage between the source and drain of the second transistor is higher than a breakdown voltage between the source and drain of the first transistor.

### Claim 17 (depends on 12)

The circuit of claim 12, wherein the voltage at the drain of the first transistor is equal to the supply voltage minus a threshold voltage of the first transistor.

### Claim 18 (depends on 12)

The circuit of claim 12, wherein the supply voltage ranges from 1.6 V to 3.9 V.

### Claim 19 (depends on 12)

The circuit of claim 12, wherein a current flowing through the source and drain of the first transistor ranges from 10 μA to 70 μA.