Title :
A 70-MHz continuous-time CMOS band-pass ΣΔ modulator for GSM receivers
Author :
Hsu, Issac ; Luong, Howard C.
Author_Institution :
Dept. of Electr. & Electron. Eng., Hong Kong Univ. of Sci. & Technol., Kowloon, China
Abstract :
A 70-MHz continuous-time CMOS band-pass ΣΔ modulator for GSM receivers is presented. Impulse-invariant-transformation is used to transform a discrete-time loop-filter transfer function into continuous-time. The continuous-time loop-filter is implemented using a transconductor-capacitor (Gm-C) filter. A latched-type comparator and a true-single-phase-clock (TSPC) D flip-flop are used as the quantizer of the ΣΔ modulator. Implemented in a MOSIS HP 0.5-μm CMOS technology, the chip area is 857 μm×420 μm, and the total power consumption is 39 mW. At a supply voltage of 2.5 V, the maximum SNDR is measured to be 42 dB, which corresponds to a resolution of 7 bits
Keywords :
CMOS integrated circuits; band-pass filters; cellular radio; comparators (circuits); continuous time filters; radio receivers; sigma-delta modulation; 0.5 micron; 2.5 V; 39 mW; 70 MHz; CMOS; GSM receivers; MOSIS HP; SNDR; band-pass sigma-delta modulator; chip area; continuous-time loop-filter; impulse-invariant-transformation; latched-type comparator; power consumption; quantizer; supply voltage; transconductor-capacitor filter; true-single-phase-clock D flip-flop; Circuits; Delay; Delta modulation; Feedback; Filters; Frequency; GSM; Impedance; Sampling methods; Transfer functions;
Conference_Titel :
Circuits and Systems, 2000. Proceedings. ISCAS 2000 Geneva. The 2000 IEEE International Symposium on
Conference_Location :
Geneva
Print_ISBN :
0-7803-5482-6
DOI :
10.1109/ISCAS.2000.856169
