| 摘要 |
Disclosed is a calibration apparatus and method for programmable response frequency selecting elements. The calibration apparatus comprises a basic reference source, a programmable counter, a control logic unit, and a frequency to time constant converter. The programmable counter generates plural different frequency signals required by the frequency selecting elements with different frequency responses. The frequency to time constant converter determines a calibrated capacitance through the timing control signals generated by the control logic unit. This invention makes the process, temperature, and power supply variation for frequency selecting elements free. It allows the frequency selecting elements to have a high accurate, stable, and wide range programming of frequency responses. It is suitable for multi-standard applications. It greatly reduces the chip size, and significantly lowers down the cost for the applications.
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