1-mS constant-Gm GaN transconductor with embedded process compensation

This paper presents the design of a GaN constant-Gm transconductor for smart-power applications. The proposed solution exploits source degeneration to linearize the transconductance and three cascode current mirrors to increase the transconductance and provide differential to single-ended conversion. Moreover, a biasing section is added to cope with the wide process spread, especially in threshold voltages, of both enhancement and depletion GaN transistors. Nominal simulation results show that the proposed transconductor, supplied from 6-V and biased with 655 μ A provides 1 mS transconductance, within a linear differential input range of ±100 mV up to more than 10 MHz.