公开(公告)号：US11368125B2

公开(公告)日：2022-06-21

申请号：US17340593

申请日：2021-06-07

Applicant: Samsung Electronics Co., Ltd.

Inventor： Jaehong Jung ,  Wonkang Kim ,  Seungjin Kim ,  Seunghyun Oh

IPC: H03B5/36 ,  H03K5/159 ,  G06F1/10 ,  H03K5/00

Abstract: A crystal oscillator reducing phase noise and a semiconductor chip including the same are provided. The crystal oscillator includes a transconductance circuit electrically connected to a crystal, a load capacitor connected to the transconductance circuit, a feedback resistance circuit connected between an input terminal of the transconductance circuit and an output terminal of the transconductance circuit, the feedback resistance circuit configured to provide a feedback resistance, and a variable resistance controller configured to generate a resistance control signal for controlling the feedback resistance, the resistance control signal causing the feedback resistance to have a first value in a first period and a second value in a second period, the first value being less than the second value, the first period corresponding to a first portion of a cycle of the clock signal, and the second period corresponding to a second portion of the cycle different from the first portion.