Download or read book A Wideband Low-power Continuous-time Delta-Sigma Modulator for Next Generation Wireless Applications written by Xuefeng Chen and published by . This book was released on 2007 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, a wideband low-power CT DeltaSigma modulator for next generation wireless applications is proposed to achieve 10-bit dynamic range within a 25 MHz signal bandwidth. On the system level, a low-power, mainly feed-forward architecture is used to realize the loop filter. Feed-in branches are added and optimized to eliminate the out-of-band peaking in the signal transfer function. On the circuit level, two-stage operational amplifiers with class-AB output stages are used to implement low-power active RC integrators. Capacitor tuning is used to compensate the variation of RC time constants. In addition, a fast current adder, an 11-level internal flash ADC and three current feedback DACs are also integrated on the chip which was manufactured in TSMC 0.18 mum CMOS technology. The test results show that the modulator draws less than 10 mA from the 1.8 V supply voltage.