A CMOS multi-gain transconductance amplifier and its applications

Transconductance amplifier (g(m)) based circuits are attractive due to their inherent programmability features. Single output g(m)'s are often replaced by multi-output g(m)'s to reduce the number of active devices for a given application. However, this usually results in losing the circuit programmability features. This work shows that this problem can be circumvented through adopting a new programmable multi-gain g(m). The advantages of the proposed multi-gain g(m) are demonstrated using two filter design examples. They show that the proposed multi-gain g(m) reduces the number of active devices by two-third compared with their single output g(m) based counterparts while maintaining their versatile programmability characteristics. Experimental results obtained from a 0.18 mu m CMOS process for one of the applications are provided.