Analog filters for audio frequency range based on current starved CMOS inverter

In the paper the measurement results obtained for audio frequency range CMOS analog filters implemented entirely on-chip are presented. The filter itself was primarily dedicated for non-uniform sampling delta modulator codec. For several reasons the experimental chip containing the filter under consideration has been manufactured twice with minor layout changes, thus the experimental data allow to discuss both mismatch as well as process variation impact on filter performance. The tuning capability, dynamic range as well as substrate noise immunity are also discussed.