US 11,906,994 B2
Power supply circuit, corresponding device and method
Daniele Mangano, San Gregorio di Catania (IT); Andrei Tudose, Chateauneuf (FR); Francesco Clerici, Aci Castello (IT); and Pasquale Butta', Messina (IT)
Assigned to STMicroelectronics S.r.l., Agrate Brianza (IT); and STMicroelectronics (Rousset) SAS, Rousset (FR)
Filed by STMicroelectronics S.r.l., Agrate Brianza (IT); and STMicroelectronics (Rousset) SAS, Rousset (FR)
Filed on Jun. 9, 2022, as Appl. No. 17/836,524.
Claims priority of application No. 102021000015197 (IT), filed on Jun. 10, 2021.
Prior Publication US 2022/0397923 A1, Dec. 15, 2022
Int. Cl. G06F 1/00 (2006.01); G05F 1/46 (2006.01); G06F 1/3296 (2019.01)
CPC G05F 1/468 (2013.01) [G06F 1/3296 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A circuit, comprising:
a first node configured to receive a first voltage;
a second node configured to provide electrical supply power for output;
a first voltage regulator coupled to the first node and the second node and configured to provide a first regulated voltage at the second node;
wherein the first voltage regulator is activatable in a first mode of operation for startup during which the first voltage regulator applies to said second node a voltage that increases towards a supply threshold;
a power on reset circuit having an input receiving the voltage at said second node and configured to assert an enable signal when the increase of the voltage at said second node reaches the supply threshold;
a second voltage regulator coupled to the first node and configured to provide a second regulated voltage at a third node, wherein said second voltage regulator is activated in response to assertion of the enable signal; and
control circuitry powered by the second regulated voltage at the third node and configured, when the second voltage regulator is activated, to control a change of the first voltage regulator to a second mode of operation where a regulated voltage higher than said supply threshold is applied to said second node, and further configured, when low-power operation request signal is received, to control a change of the first voltage regulator to a third mode of operation providing low power operation at the second node and to deassert the enable signal to deactivate the second voltage regulator.