Silicon Laboratories Inc.
Compensating for thermal lag in temperature compensated crystal oscillators

Abstract:

A temperature compensated crystal oscillator (TCXO) includes a crystal oscillator and a temperature sensor to provide a sensed temperature. A delay circuit has a selectable delay to delay the frequency compensation based on the sensed temperature. The delay compensates for a difference between when the temperature sensor reflects a change in temperature and when a frequency of a signal supplied by the crystal oscillator is affected by the change in temperature. The delay may be static or dynamic with respect to the current temperature sensed by the temperature sensor.