An Inverter-Based Difference Differential Amplifier with Active Frequency Compensation

This work presents an improved circuit of the Difference Differential Amplifier (DDA) based on Nauta's inverter-based fully-differential amplifier. The proposed topology keeps the original Nauta DDA as the first stage and adds a second stage with feedforward common-mode cancellation and active frequency compensation. The circuit achieves 88 dB differential gain, 88 dB CMRR, 88 dB PSRR, 17.5 MHz GBW for a 15 pf load while consuming 1.17 mA for a 1.8 V supply voltage at room temperature.