公开(公告)号：US11705861B1

公开(公告)日：2023-07-18

申请号：US17853070

申请日：2022-06-29

Applicant: Silicon Laboratories Inc.

Inventor： Mohamed M. Elkholy ,  Francesco Barale ,  Tiago Pinto Guia Marques ,  Steffen Skaug ,  Håkon Børli

IPC: H03B5/06 ,  H03B5/36 ,  H03L7/099

CPC classification number: H03B5/06 ,  H03B5/36 ,  H03B5/364 ,  H03L7/099 ,  H03B2200/0012

Abstract: A first three state driver injects a first clock signal into a crystal through an input node during a startup phase of a crystal oscillator and a second three state driver injects a second signal into the crystal through an output node during the startup phase. The first and second signals are anti-phase signals. The crystal oscillator circuit includes a first amplifier that is used during starting up and steady-state operation and includes a second amplifier. The injection through the input and output nodes is disabled after a fixed time. After injection ends, the second amplifier is turned on if voltage on the output node has reached a desired voltage and left off otherwise. If the second amplifier is turned on, the second amplifier is turned off when the voltage on the output node reaches the desired voltage.

公开(公告)号：US10175707B1

公开(公告)日：2019-01-08

申请号：US15626425

申请日：2017-06-19

Applicant: Silicon Laboratories Inc.

Inventor： Li Wei ,  Steffen Skaug

IPC: G05F1/575 ,  H02M3/158 ,  H02M1/00

Abstract: In an example, an apparatus includes: a pass device coupled between a supply voltage node and a load circuit and to provide a regulated voltage to the load circuit in response to a control signal received at a control terminal of the pass device; a first amplifier to compare a reference voltage to the regulated voltage and to output a comparison signal at a comparison node in response to the comparison; a second amplifier having an input device having a control terminal coupled to the comparison node to receive the comparison signal and to output the control signal to the pass device based at least in part in response to the comparison signal; and a feedback circuit to provide a feedback signal to the first amplifier based at least in part on a load current of the load circuit.