公开(公告)号：US10146240B1

公开(公告)日：2018-12-04

申请号：US15886700

申请日：2018-02-01

Applicant: Apple Inc.

Inventor： Ruopeng Wang ,  Dashun Xue ,  Jiandong Jiang ,  Jay B. Fletcher

IPC: G05F3/16 ,  G05F1/575 ,  H02M7/10 ,  G05F3/24

Abstract: A voltage regulator having a pre-regulator circuit is disclosed. A low dropout (LDO) voltage regulator includes an amplifier circuit, a current buffer circuit, and a pre-regulator circuit. The current buffer circuit includes a transistor having a gate terminal coupled to the amplifier output. The current buffer provides a current based at least in part on the output signal generated by the amplifier. The pre-regulator circuit is coupled to provide a dynamic supply voltage to the current buffer. They dynamic supply voltage depends at least in part on a fixed supply voltage provided thereto, as well as the output voltage provided by the LDO voltage regulator.