US 12,031,822 B2
Physical quantity detection circuit, physical quantity sensor, electronic instrument, vehicle, and method for diagnosing failure of physical quantity sensor
Takashi Aoyama, Chino (JP)
Assigned to SEIKO EPSON CORPORATION, (JP)
Filed by SEIKO EPSON CORPORATION, Tokyo (JP)
Filed on Jun. 23, 2023, as Appl. No. 18/340,272.
Application 18/340,272 is a continuation of application No. 17/675,110, filed on Feb. 18, 2022, granted, now 11,733,045.
Application 17/675,110 is a continuation of application No. 16/855,073, filed on Apr. 22, 2020, granted, now 11,300,411, issued on Apr. 12, 2022.
Claims priority of application No. 2019-081621 (JP), filed on Apr. 23, 2019.
Prior Publication US 2023/0332891 A1, Oct. 19, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G01C 19/5776 (2012.01); H03F 3/45 (2006.01)
CPC G01C 19/5776 (2013.01) [H03F 3/45 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A physical quantity detection circuit comprising:
a drive circuit to undergo the excited vibration for a physical quantity detection device that detects a physical quantity;
a differential amplification circuit that differentially amplifies a signal pair based on a first signal and a second signal output from the physical quantity detection device;
a first synchronous wave-detection circuit for synchronously detecting a signal based on the output signal of the differential amplification circuit;
a physical quantity detection signal generation circuit that generates a physical quantity detection signal based on the output signal of the first synchronous detection circuit;
an adder circuit that adds the signal pair;
a second synchronous wave-detection circuit that performs synchronous wave-detection on a signal based on the output signal from the adder circuit; and
a vibration leakage signal generation circuit that generates a vibration leakage signal based on an output signal from the synchronous wave-detection circuit.