Wide gm adjustment range highly linear OTA with programmable mirrors operating in triode mode

A new very compact and highly linear CMOS OTA, with very wide gain tuning range, is presented. It uses a fixed gain linear V-I converter input stage and electronically programmable current mirrors working in triode which are very compact and continuously adjustable. Programmability is achieved by tuning VDS of the mirroring transistors. The OTA input range and bandwidth is approximately independent of gain adjustment. Simulation results in 0.5μm CMOS technology verify the characteristics of the proposed OTA with distortion less than 0.5% over the entire tuning range.