US 12,079,022 B2
Low voltage high precision power detect circuit with enhanced power supply rejection ratio
Seyedeh Sedigheh Hashemi, Santa Clara, CA (US); Vahid Majidzadeh Bafar, Campbell, CA (US); Ali Mesgarani, Santa Clara, CA (US); and Mansour Keramat, Los Gatos, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Oct. 24, 2023, as Appl. No. 18/493,796.
Application 18/493,796 is a continuation of application No. 17/181,950, filed on Feb. 22, 2021, granted, now 11,841,726.
Application 17/181,950 is a continuation of application No. 16/288,253, filed on Feb. 28, 2019, granted, now 10,928,846, issued on Feb. 23, 2021.
Prior Publication US 2024/0168508 A1, May 23, 2024
Int. Cl. G05F 3/26 (2006.01); G05F 3/20 (2006.01); G11C 5/14 (2006.01); G11C 11/4074 (2006.01)
CPC G05F 3/26 (2013.01) [G05F 3/205 (2013.01); G11C 5/147 (2013.01); G11C 11/4074 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a power detection circuit configured to generate a first indication in response to detecting that an external supply voltage is less than a first threshold voltage, wherein the power detection circuit includes:
a bandgap circuit configured to generate the first threshold voltage using one of a first voltage or a second voltage;
a switch control circuit configured to cause the bandgap circuit to receive the first voltage or the second voltage dependent on a level of the external supply voltage; and
a first comparator configured to generate a first indication using the first threshold voltage and the external supply voltage;
a power management circuit configured to perform one or more power control actions based on a level of the first indication.