Common reference crystal systems

A technology of crystal oscillator and crystal resonator, which is applied in the direction of synchronization/start-stop system, radio wave measurement system, satellite radio beacon positioning system, etc.
CN103457601AInactive Publication Date: 2013-12-18BROADCOM CORP
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
BROADCOM CORP
Publication Date
2013-12-18
Estimated Expiration
Not applicable · inactive patent

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Abstract

One embodiment of communication system comprises a crystal oscillator configured to output a reference clock; cellular radio frequency (RF) and baseband phase locked loops configured to receive the reference clock within a cellular module and compensate for calculated frequency errors between a received cellular downlink signal and a cellular local oscillator signal during operation of the cellular module; global positioning system (GPS) frequency compensation circuitry configured to receive the reference clock within a GPS module and compensate for calculated frequency errors during operation of the GPS module; and a temperature sensing circuit which includes a plurality of sensing resistors and is configured to output a signal corresponding to a temperature of a reference crystal which is translated to a frequency deviation, wherein the (GPS) frequency compensation circuitry is configured to offset the frequency deviation and output a temperate compensated signal to meet GPS clock frequency requirements.
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Description

technical field

[0001] The present disclosure generally relates to reference crystal oscillators for co-integrated communication systems and stand-alone systems. Background technique

[0002] In recent years, cellular communication solutions have been converted to lower cost uncompensated quartz piezoelectric crystal solutions. However, due to the stringent maximum frequency transition speed and maximum frequency step change requirements of the GPS system, these low-cost (crystalline) cellular solutions cannot inherently translate into a cellular and Global Positioning System (GPS) system within a single mobile platform A low-cost (uncompensated) crystal solution that is common and shared. In prior art implementations, the stringent maximum frequency slew speed and maximum frequency step change requirements of the GPS system typically necessitated the inclusion of a temperature compensated crystal oscillator (also known as a TCXO) for use as the reference oscillator for the...

Claims

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