公开(公告)号：US20240171161A1

公开(公告)日：2024-05-23

申请号：US18223537

申请日：2023-07-18

Applicant: MEDIATEK INC.

Inventor： Chien-Wei Chen ,  Kairen Fong ,  Chao-Ching Hung ,  Yu-Li Hsueh

IPC: H03K5/01 ,  G04F10/00 ,  H03K3/037

CPC classification number: H03K5/01 ,  G04F10/005 ,  H03K3/037

Abstract: A frequency calibration (FCAL) circuit and a method for calibrating an oscillation frequency of a controllable oscillator are provided. The FCAL circuit includes the controllable oscillator, a divider, a time-to-digital converter (TDC) and a calibration logic. The controllable oscillator generates a controllable oscillation clock according to a calibration code. The divider divides the oscillation frequency of the controllable oscillation clock by a predetermined divisor to generate a divided clock. The TDC converts a first period between first edges of a reference clock and the divided clock into a first period code and converts a second period between second edges of the reference clock and the divided clock into a second period code. The calibration logic compares the first period code and the second period code to generate a comparison result for determining whether the first period is greater or less than the second period, and accordingly controls the calibration code.