A 1.5V class A 5/sup th/ order log domain filter in SiGe technology

This paper presents a class A 5/sup th/ order Butterworth log domain filter fabricated in IBM's 6HP SiGe technology. The filter is synthesized from an RLC ladder prototype and has a maximum cutoff frequency of 2 MHz. At operating supply voltages down to 1.5V, the filter consumes 330 /spl mu/W of power, has an output noise of 70 nA rms, an IIP3 of 95 /spl mu/A rms, and it is tunable over two decades of frequency.