# US 2013/0154604 A1 · Reference current generation circuit and reference voltage generation circuit

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- Number: US 2013/0154604 A1
- Document ID: US20130154604A1
- Status: Published application
- Kind: A1
- Application number: 13/672,213
- Filed: 2012-11-08
- Published: 2013-06-20
- Earliest claimed: 2011-12-15
- Assignees: Seiko Instruments Inc.
- Inventors: Masakazu SUGIURA
- Web page: https://patentgrep.com/patent/US20130154604A1

## CPC

- G05F 3/30: Regulators using the difference between the base-emitter voltages of two bipolar transistors operating at different current densities (G05F3/26 takes precedence)
- G05F: SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES

## Abstract

Provided are a reference current generation circuit and a reference voltage generation circuit, which have improved response speed when power supply is activated or fluctuates. In order to reduce a load capacitance of an operational amplifier, a transistor for providing a current to a transistor pair having a common gate-source voltage is provided, and the operational amplifier controls an ON-state resistance of the transistor.

## Claims

### Claim 1

A reference current generation circuit, comprising:
a first PN junction;
a first transistor for causing a current to flow through the first PN junction;
a first resistor and a second PN junction connected in series;
a second transistor for causing a current to flow through the first resistor and the second PN junction;
a first voltage source for supplying a common voltage to gates of the first transistor and the second transistor;
a first operational amplifier including a first input terminal for inputting a voltage generated in the first PN junction and a second input terminal for inputting a voltage generated in the first resistor and the second PN junction; and
a third transistor including a gate controlled by an output voltage of the first operational amplifier, for supplying a current to the first transistor and the second transistor.

### Claim 2 (depends on 1)

A reference current generation circuit according to claim 1, further comprising:
a second resistor connected in parallel to the first PN junction; and
a third resistor connected in parallel to the first resistor and the second PN junction.

### Claim 3 (depends on 1)

A reference voltage generation circuit, comprising:
the reference current generation circuit according to claim 1;
a fourth resistor and a third PN junction connected in series; and
a fourth transistor including a gate connected in common to the gate of the third transistor, for causing a current to flow through the fourth resistor and the third PN junction.

### Claim 4 (depends on 2)

A reference voltage generation circuit, comprising:
the reference current generation circuit according to claim 2;
a fourth resistor; and
a fourth transistor including a gate connected in common to the gate of the third transistor, for causing a current to flow through the fourth resistor.

### Claim 5 (depends on 1)

A reference voltage generation circuit, comprising:
the reference current generation circuit according to claim 1;
a fourth resistor;
a fourth transistor including a gate connected in common to the gate of the third transistor, for causing a current to flow through the fourth resistor;
a fifth transistor and a fifth resistor connected in series;
a second operational amplifier including a first input terminal connected to a connection node between the fifth transistor and the fifth resistor, a second input terminal connected to one of the first input terminal and the second input terminal of the first operational amplifier, and an output terminal connected to a gate of the fifth transistor; and
a current-mirror circuit for causing a current of the fifth transistor to flow through the fourth resistor.