US 11,698,306 B2
Digital-output temperature sensor, circuit device, and oscillator
Akio Tsutsumi, Chino (JP); and Hideo Haneda, Shiojiri (JP)
Assigned to SEIKO EPSON CORPORATION
Filed by Seiko Epson Corporation, Tokyo (JP)
Filed on Feb. 25, 2022, as Appl. No. 17/680,680.
Claims priority of application No. 2021-029711 (JP), filed on Feb. 26, 2021.
Prior Publication US 2022/0276100 A1, Sep. 1, 2022
Int. Cl. G01K 7/01 (2006.01); H03M 1/00 (2006.01); H03B 5/04 (2006.01)
CPC G01K 7/01 (2013.01) [H03B 5/04 (2013.01); H03M 1/001 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A digital-output temperature sensor comprising:
a temperature sensor circuit configured to detect temperature to output a temperature detection current;
a current mirror circuit which is configured to make a mirror current of the temperature detection current flow into a first output node as a source current, and pull in a mirror current of a reference current from the first output node as a sink current to thereby output a first difference current from the first output node, and which is configured to make the mirror current of the reference current flow into a second output node as the source current, and pull in the mirror current of the temperature detection current from the second output node as the sink current to thereby output a second difference current from the second output node;
a chopping circuit configured to perform a chopping operation on at least one transistor of a plurality of the current mirror circuit; and
an A/D conversion circuit configured to perform an A/D conversion of the first difference current and the second difference current as a differential pair, wherein
the chopping circuit is configured to perform the chopping operation of making the mirror current of the reference current flow in a second state through the at least one transistor of the current mirror circuit through which the mirror current of the temperature detection current flows in a first state, and making the mirror current of the temperature detection current flow in the second state through the at least one transistor of the current mirror circuit through which the mirror current of the reference current flows in the first state.