US 12,231,115 B2
Threshold detector of a power on reset circuit with improved accuracy for switching levels over temperature variations
Andrea Bonelli, Eindhoven (NL); and Stefania Chicca, Eindhoven (NL)
Assigned to ams International AG, Jona (CH)
Appl. No. 17/429,798
Filed by ams International AG, Jona (CH)
PCT Filed Feb. 12, 2020, PCT No. PCT/EP2020/053601
§ 371(c)(1), (2) Date Aug. 10, 2021,
PCT Pub. No. WO2020/165250, PCT Pub. Date Aug. 20, 2020.
Claims priority of provisional application 62/856,982, filed on Jun. 4, 2019.
Claims priority of provisional application 62/804,267, filed on Feb. 12, 2019.
Prior Publication US 2022/0131538 A1, Apr. 28, 2022
Int. Cl. H03K 17/22 (2006.01); H03K 17/14 (2006.01)
CPC H03K 17/22 (2013.01) [H03K 17/14 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A power on reset circuit comprising:
a threshold detector circuit including:
a terminal configured to sense a power supply voltage to an electrical device;
a voltage comparator having first and second input terminals, the voltage comparator further having an output terminal to provide a reset signal;
first circuitry operable to convert the power supply voltage to a sensed current, wherein the first circuitry provides a positive temperature coefficient to the sensed current;
second circuitry operable to generate, based on the sensed current, a temperature-dependent voltage corresponding to the power supply voltage and to couple the temperature-dependent voltage to the first input of the voltage comparator; and
third circuitry operable to generate, based on the sensed current, a reference voltage and to couple the reference voltage to the second input of the voltage comparator,
wherein the first circuitry forms a current mirror with the second circuity and with the third circuitry;
further comprising a pulse width generator, wherein the pulse width generator is operable to receive the reset signal and generate a control signal for initializing one or more components of an electronic device based on the reset signal.