The ultra-multi-tanh technique for bipolar linear transconductance amplifiers

A novel circuit design technique for bipolar linear transconductance amplifiers is presented. A triple-tail cell, which consists of three emitter-common transistors biased only by a current source, is exchangeable with symmetrical cross-coupled, emitter-coupled pairs in a multi-tanh cell, such as a multi-tanh doublet, or a multi-tanh quad. Therefore, the multi-tanh technique is further theoretically expanded to the ultra-multi-tanh technique. In this paper, the ultra-multi-tanh technique is proposed and discussed, and furthermore, an ultra-multi-tanh doublet is verified with bipolar transistor-arrays and discrete resistors on a breadboard.