A programmable digitally-tuned CMOS OTA-C bandpass filter architecture for high-accuracy applications

An architecture is presented of a digitally programmable CMOS OTA-C (operational transconductance amplifier and capacitor) analog filter which is controlled, characterized, and tuned by a microprocessor in the field. Two elements of this architecture, the highly accurate performance measurement system and the tuning algorithm are discussed in detail. Experimental results show that this versatile architecture is suitable for high-accuracy, high-frequency, or high-Q continuous-time filtering applications, as well as those requiring in-field self-tests or in-field programming.<>