Patent Number: 8,575,981

Title: MEMS-based frequency synthesizers with enhanced temperature compensation

Abstract: A frequency synthesizer is configured to generate a periodic output signal in response to a periodic input signal and a temperature-dependent frequency adjusting control signal. A temperature sensor is provided, which is configured to generate a temperature measurement signal in response to detecting a temperature of at least a portion of the frequency synthesizer. A control circuit is provided, which is configured to generate the temperature-dependent frequency adjusting control signal in response to the temperature measurement signal. This control circuit includes a cascaded arrangement of an oversampled data converter and a multi-stage digital filter, which is configured to generate a plurality of codes from respective ones of the digital filter stages, and a selection circuit, which is configured to use at least first and second ones of the plurality of codes in sequence during first and second consecutive time intervals to generate the temperature-dependent frequency adjusting control signal.

Inventors: Chen; Chien Chen (San Jose, CA), Lo; YuanHeng (San Jose, CA), Alli; Pavan Kumar (Sunnyvale, CA), Lo; Yongchou (Cupertino, CA), Yan; Minhui (San Jose, CA), Bhugra; Harmeet (San Jose, CA)

Assignee: Integrated Device Technology, Inc.

International Classification: H03L 7/06 (20060101)

Expiration Date: 1/05/12017