A 75.1dB SNDR, 80.2dB DR, 4th-order feed-forward continuous-time sigma-delta modulator with hybrid integrator for silicon TV-tuner application

A 4th-order resistive feed-forward continuous time sigma-delta modulator (CTSDM) for a worldwide analog/digital TV-receiver is presented. The proposed hybrid integrator of the modulator is developed in order to save the summing amplifier and reduce total area. In addition, the modulator incorporates the proposed low power operational amplifiers (op-amp) with active feed-forward compensation to reduce power consumption in the loop filter. The prototype chip is implemented in a 55nm CMOS process which occupies 0.132 mm
²
. Measurements show that the proposed modulator achieves 80.2dB dynamic range, 75.1dB SNDR, and an effective number of bits (ENOB) of 12.2 bits over 5 MHz signal bandwidth. The figure of merit (FOM) is 0.28 pJ/conversion at 1.3 V supply.