公开(公告)号：US20170346406A1

公开(公告)日：2017-11-30

申请号：US15354705

申请日：2016-11-17

Applicant: Apple Inc.

Inventor： Bogdan T. Bucheru ,  Zaohong Yang

IPC: H02M3/335

CPC classification number: H02M3/33523 ,  H02M3/33507 ,  H02M3/33553 ,  H02M2001/0025

Abstract: This disclosure describes an AC/DC power converter that produces multiple output voltage levels. The AC/DC power converter may include a gain adjustment circuit. The gain adjustment circuit may adjust the gain of a feedback signal of the converter in accordance with the converter's output voltage level. The gain adjustment circuit provides sufficient gain and phase margins to the converter and thus enhances the converter's stability.

公开(公告)号：US09768703B2

公开(公告)日：2017-09-19

申请号：US14985040

申请日：2015-12-30

Applicant: Apple Inc.

Inventor： Zaohong Yang ,  Bharatkumar K. Patel ,  Bogdan T. Bucheru ,  Juan Carlos Pastrana

IPC: H02M3/315 ,  H02M3/335 ,  H02M1/32 ,  H02M1/00

CPC classification number: H02M3/33592 ,  H02M1/32 ,  H02M2001/0032 ,  H02M2001/0038 ,  H02M2001/0054 ,  Y02B70/1475 ,  Y02B70/1491 ,  Y02B70/16

Abstract: The disclosed embodiments provide a system that operates a flyback converter. During activation of a synchronous rectifier (SR) controller on a secondary side of the power converter, the system temporarily disables driving of a gate of a metal-oxide-semiconductor field-effect transistor (MOSFET) by the SR controller to enable synchronization of the SR controller to a switching frequency on a primary side of the power converter. After driving of the gate of the MOSFET by the SR controller has been disabled for a pre-specified period, the system enables driving of the gate of the MOSFET by the SR controller.