A versatile 1.75mW CMOS continuous-time delta-sigma ADC with 75dB dynamic range for wireless applications

An ultra low power continuous-time 2nd order delta-sigma modulator fabricated in 0.18u CMOS operates at 1.8V, dissipates 1.75mW, and occupies 0.36mm². The prototype modulator features the option of either a lowpass or bandpass quantization noise transfer function to investigate the performance of this ADC technology in lowpass and bandpass applications. The measured performance over a 200kHz bandwidth in lowpass mode is 75dB dynamic range, while the measured performance over a 1 MHz band around a 2MHz IF is 53dB dynamic range. This level of performance makes the ADC suitable for various wireless applications such as GSM and Bluetooth transceivers.