| 摘要 |
A temperature compensation circuit (10) for a crystal oscillator programmed by a single component (12), such as a resistor. The component (12) provides a voltage to an A/D converter (26). The digital signals (28) from the A/D converter (26) are divided and directed to separate signal generators (44,46,48,50,56) which control different aspects of the temperature compensation circuit (10). These aspects include a hot, cold, linear, balance and warp adjustment. The temperature compensation circuit (10) drives a varactor (18) which reactively loads a crystal oscillator (14) to compensate frequency over temperature. By using a single component (12) to program the circuit (10), an EEPROM is no longer needed which saves IC space and reduces IC processing steps, and the use of multiple external components to perform a compensation is avoided which further saves physical space.
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