An offset compensated CMOS current-feedback operational-amplifier

A new CMOS current-feedback operational-amplifier (CFOA) with a novel on-chip current-mode input offset voltage compensation circuit is presented. The offset voltage is reduced to less than 1 mV by varying the bias currents of the amplifier's input buffer as a function of the mismatch between the NMOS and PMOS V/sub t/'s (V/sub in/ and V/sub tp/). The proposed compensation technique is suitable for both CMOS and BJT CFOA designs without degrading their high-frequency performance. As well, it is irrespective of process and temperature parameters because of its fully symmetrical architecture. Results of HSPICE simulation show that a GBW of around 100 MHz and a supply current of around 300 /spl mu/A are achievable in a CMOS CFOA.