A three bit second order audio band delta sigma modulator with 98.2dB SQNR

A three bit second order delta sigma modulator for audio applications implemented in 130nm CMOS technology is presented. The modulator features two integrators, a flash quantizer and two current steering DACs. In order to minimize the effect of delays in the DACs, excessive loop delay (ELD) compensation is utilized. Using an oversampling ratio (OSR) of 80, the design consumes 2.8mW and achieves a simulated signal to quantization noise ratio (SQNR) of 98.2dB. The chip area is minimized by decreasing the number of digital to analog converters (DACs) by using the concept of partial integration. The compact design occupies an active core area of 630μm × 600μm