US 12,480,981 B2
Voltage sensor with in-range check for safety-critical applications
Anatoly Gelman, San Diego, CA (US); Felipe Regis Goncalves Cabral, Crosshaven (IE); Mingcheng Zhu, San Diego, CA (US); and Amit Aneja, Chandler, AZ (US)
Assigned to QUALCOMM Incorporated, San Diego, CA (US)
Filed by QUALCOMM Incorporated, San Diego, CA (US)
Filed on Feb. 15, 2024, as Appl. No. 18/442,774.
Prior Publication US 2025/0264505 A1, Aug. 21, 2025
Int. Cl. G01R 19/165 (2006.01); G01R 19/25 (2006.01); H03K 3/03 (2006.01)
CPC G01R 19/1659 (2013.01) [G01R 19/25 (2013.01); H03K 3/0315 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a multi-phase ring oscillator (RO) configured to operate in a first voltage domain;
a frequency counter coupled to the multi-phase RO, the frequency counter configured to accumulate a plurality of phase cycles from the multi-phase RO over a time duration to generate a digital count word;
an alarm processor coupled to the frequency counter, the alarm processor configured to receive an alarm state signal from the frequency counter; and
a heartbeat detector coupled to the multi-phase RO, the heartbeat detector configured to operate in a second voltage domain and configured to detect a periodic recurrence of a heartbeat pulse to determine an integrity of the alarm state signal and an overall sensor operation.