A low-voltage fully balanced OTA with common mode feedforward and inherent common mode feedback detector

A pseudo differential fully balanced CMOS OTA architecture with inherent common mode detection is proposed. Through judicious arrangement, the common-mode feedback circuit can be economically implemented. The OTA achieves a good CMRR and is suitable for low voltage operation. As an example of the applications of the proposed OTA, a 100MHz 4th order linear phase OTA-C filter is presented. The measured group delay ripple is 3%, the filter dynamic range is 45dB. It consumes 42.9mW per complex poles.