US 9,812,972 B2
Wake up management circuit for a switching converter and related wake up method
Salvatore Tumminaro, Marianopoli (IT); Andrea Rapisarda, Motta S. Anastasia (IT); and Alfio Pasqua, Piedimonte Etneo (IT)
Assigned to STMicroelectronics S.r.l., Agrate Brianza (IT)
Filed by STMicroelectronics S.r.l., Agrate, Brianza (IT)
Filed on Oct. 20, 2016, as Appl. No. 15/298,518.
Application 15/298,518 is a continuation of application No. 14/644,452, filed on Mar. 11, 2015, granted, now 9,520,769.
Claims priority of application No. MI2014A0799 (IT), filed on Apr. 30, 2014.
Prior Publication US 2017/0040901 A1, Feb. 9, 2017
Int. Cl. H02M 1/36 (2007.01); H02M 3/335 (2006.01); H02M 1/08 (2006.01); H02M 1/00 (2006.01)
CPC H02M 3/33507 (2013.01) [H02M 1/08 (2013.01); H02M 1/36 (2013.01); H02M 3/33515 (2013.01); H02M 3/33523 (2013.01); H02M 2001/0009 (2013.01); H02M 2001/0035 (2013.01); Y02B 70/16 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A control circuit for a switching converter, comprising:
a first sensing circuit configured to detect a change in voltage at a secondary winding of a transformer;
a second sensing circuit configured to detect current flow in a primary winding of the transformer;
a third sensing circuit configured to detect a voltage in an auxiliary winding of the transformer;
a pulse width modulation (PWM) drive circuit configured to control said current flow in the primary winding of the transformer in response to the detected current flow and a control signal indicating a desired current flow;
a comparator circuit configured to compare the detected voltage in the auxiliary winding to a reference voltage and generate a compare signal;
a wakeup circuit responsive to the detected change in voltage at the secondary winding and configured to generate a reference signal; and
a multiplexing circuit configured to select between the compare signal and the reference signal for application as the control signal to the PWM drive circuit;
wherein said wakeup circuit further responds to the detected change in voltage at the secondary winding by causing the multiplexing circuit to select the reference signal.