| 摘要 |
A low pass filter includes a switchable resistor bank, a gain stage, and a capacitor bank. The resistors and capacitors switched into the circuit determine a cutoff frequency of the low pass filter. Frequency programmability may be obtained using the switchable resistor bank implemented as a parallel bank of binary weighted resistors. Further frequency programmability may be obtained using the switchable capacitor bank in conjunction with the switchable resistor bank. The resistor and capacitor processes in a semiconductor wafer are sufficiently accurate and repeatable so as to minimize any necessary calibration.
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