US 11,736,009 B2
Zero current temporal threshold for switching to a low power mode
Michele Suraci, Varese (IT); and Marco Borghese, Milan (IT)
Assigned to STMicroelectronics S.r.l., Agrate Brianza (IT)
Filed by STMicroelectronics S.r.l., Agrate Brianza (IT)
Filed on Sep. 23, 2021, as Appl. No. 17/482,961.
Claims priority of application No. 102020000023299 (IT), filed on Oct. 2, 2020.
Prior Publication US 2022/0109369 A1, Apr. 7, 2022
Int. Cl. H02M 3/158 (2006.01); H02M 1/00 (2006.01)
CPC H02M 3/158 (2013.01) [H02M 1/0032 (2021.05)] 16 Claims
OG exemplary drawing
 
1. A control circuit comprising:
a low-power detection circuit configured to generate a control signal, wherein the low-power detection circuit is, when a driver circuit operates in a high-power mode, configured to:
determine a first temporal value indicative of a duration of a second phase (T2);
detect whether a logic level of a zero current signal changes from a first logic level to a second logic level during the second phase (T2);
in response to detecting that the logic level of the zero current signal changes from the first logic level to the second logic level, determine a second temporal value indicative of a time (TZC) elapsed between an instant (t3) when the logic level of the zero current signal changes from the first logic level to the second logic level during the second phase (T2) and the instant (t1) when the second phase (T2) ends;
determine whether a ratio between the second temporal value (TZC) and the first temporal value (T2) is greater than a given number threshold value (TH);
in response to determining that the ratio between the second temporal value (TZC) and the first temporal value (T2) is smaller than the given threshold value (TH), set a comparison signal to the first logic level indicating that the high-power mode is to be maintained;
in response to determining that the ratio between the second temporal value (TZC) and the first temporal value (T2) is greater than the given threshold value (TH), set the comparison signal to the second logic level indicating that a low-power mode is to be activated; and
set the logic level of the control signal as a function of the comparison signal.