A 10 MHz elliptic log-domain filter in a standard CMOS process

A third order elliptic log-domain filter, fabricated in 0.35 μm CMOS technology, is presented. Lateral bipolar transistors inherent to standard CMOS processes and strongly-inverted MOSFET transistors have been used in this work to map traditional bipolar circuitry into CMOS technology. Experimental measurements demonstrate, that bandwidths of up to 10 MHz and dynamic ranges on the order of 40 dB can be achieved using these devices, and that both poles and zeros can be accurately placed using the described design techniques. Log-domain filters based on lateral PNP devices hold the potential of operating at higher frequencies than log-domain filters designed using subthreshold-MOS devices.