Reference current source

Patent metadata

Field	Value
Publication number	US-12055966-B2
Application number	US-202217706835-A
Country	US
Kind code	B2
Filing date	Mar 29, 2022
Priority date	Mar 31, 2021
Publication date	Aug 6, 2024
Grant date	Aug 6, 2024

Abstract

A reference current source includes a reference current path, a first output current path and a second output current path. The reference current path includes a diode-connected first transistor, a diode-connected second transistor, and a first resistor that are connected in series between a first fixed potential and a second fixed potential. The first output current path includes a third transistor having a gate connected to a gate of the second transistor, forming a current mirror together with the second transistor, and a second resistor interposed between the third transistor and the first fixed potential. The second output current path includes a voltage-current conversion circuit to which a potential of a third node between the third transistor and the second resistor in the first output current path is applied and through which a reference current flows.

First claim

What is claimed is:

1. A reference current source comprising:
a reference current path including a diode-connected first transistor, a diode-connected second transistor and a first resistor that are connected in series between a first fixed potential and a second fixed potential;
a first output current path including:
a third transistor having a gate connected to a gate of the second transistor, forming a current mirror together with the second transistor, and
a second resistor interposed between the third transistor and the first fixed potential; and

a second output current path including a voltage-current conversion circuit to which a potential of a node between the third transistor and the second resistor in the first output current path is applied and through which a reference current flows,
wherein
the reference current path includes a third resistor which is connected in series between the first fixed potential and the second fixed potential; and
the voltage-current conversion circuit includes:
a fourth transistor having a gate connected to the node; and
an output resistor connected between the fourth transistor and the second fixed potential.

2. The reference current source according to claim 1 , wherein a size of the second transistor is larger than a size of the third transistor.

3. The reference current source according to claim 1 ,
wherein:
the second transistor is configured of N transistors, wherein 1≤N;
the third transistor is configured of M transistors, wherein 1≤M; and
a total gate width of the N transistors constituting the second transistor is K times a total gate width of the M transistors constituting the third transistor, wherein 1<K.

4. The reference current source according to claim 1 , wherein a size of the fourth transistor is larger than a size of the first transistor.

5. The reference current source according to claim 1 , wherein a gate length of one transistor of the third transistor is 100 nm or less and 5 nm or more.

Assignees

• Thine Electronics Inc

Inventors

• Gendai Yuji
• Kubo Shunichi

Classifications

• G05F3/242 Primary

  with compensation for device parameters, e.g. channel width modulation, threshold voltage, processing, or external variations, e.g. temperature, loading, supply voltage · CPC title

• G05F1/561

  Voltage to current converters (amplifiers H03F) · CPC title

• G05F3/262 Primary

  using field-effect transistors only · CPC title

• G05F3/30 Primary

  Regulators using the difference between the base-emitter voltages of two bipolar transistors operating at different current densities (G05F3/26 takes precedence) · CPC title

• G05F1/567 Primary

  for temperature compensation · CPC title