A low-power Gm-C-based CT-ΔΣ audio-band ADC in 1.1V 65nm CMOS

A low power CT-ΔΣ is presented which achieves 92dBA of dynamic range while consuming only 110μA from a 1.1V supply in 65nm. The ADC exploits the inherent virtual ground of the ΔΣ loop to enable low power Gm-C integrators, and a simplified excess loop-delay compensation scheme. A common-mode feedback circuit which enables low voltage operation is also presented.