公开(公告)号：US11368126B1

公开(公告)日：2022-06-21

申请号：US17444320

申请日：2021-08-03

Applicant: NXP B.V.

Inventor： Ricardo Pureza Coimbra ,  Stefano Pietri ,  Vitor Moreira Gomes ,  Eduardo Ribeiro da Silva

IPC: H03B5/36 ,  H02M3/158

Abstract: A first switch is operable to couple a start-up oscillator circuit to a first crystal pin during operation in a start-up mode and decouple the start-up oscillator circuit from the first crystal pin during operation in a normal mode, and a second switch is operable to couple the start-up oscillator circuit to a second crystal pin during operation in the start-up mode and decouple the start-up oscillator circuit from the second crystal pin during operation in the normal mode. A switched oscillator circuit is coupled to the startup oscillator during operation in the startup mode, and to the first and second crystal pins during operation in the start-up and normal modes. The switched oscillator circuit includes a sample and charge circuit which is configured to sample a direct current (DC) level of the first crystal pin and pre-charge a first coupling capacitor during operation in the startup mode.