A quadrature bandpass continuous-time delta-sigma modulator for tri-mode GSM-EDGE/UMTS/DVB-T receivers, with power scaling technique

A second-order multi-bit quadrature bandpass continuous-time delta-sigma modulator (QBP-CTDSM) employing a power scaling technique (PST) is reported in this paper for GSM-EDGE/UMTS/DVB-T receivers. This modulator employs operational amplifiers with PST to optimize power consumption among the tri-mode operation. The QBP-CTDSM is fabricated in a 0.18-μm CMOS process. It achieves 81/61.2/60.9 dB SNDR across 270-kHz/5-MHz/8-MHz bandwidth with a programmable center frequency spanning from 500 kHz to 12 MHz. Measured from a 1.8-V supply voltage, the power consumptions are 4.9/8.9/12.1 mW for GSM-EDGE/UMTS/DVB-T modes, respectively, which results in FOMs of 0.99/0.95/0.84 pJ/conversion.