Switching architecture for CMOS exponential function generators eliminating squarer/multiplier circuits

A switching architecture for exponential function generators in submicron CMOS technology is proposed. The architecture is based on second-order rational approximation of exponential functions and can be realised using MOS transistors in the saturation regime. An implementation eliminating complex squarer/multiplier circuits is presented in 0.13 μm CMOS technology. Simulation results show a dB-linear range of 46 dB with less than ± 0.5 dB linear error while dissipating a maximum of 0.45 mW from a 1.2 V power supply.