A 92MHz, 80dB peak SNR SC bandpass ΣΔ modulator based on a high GBW OTA with no Miller capacitors in 0.35μm CMOS technology

被引：8

作者：

Thandri, BK ^{[1
]}

Martinez, JS ^{[1
]}

Rocha-Perez, JM ^{[1
]}

Wang, J ^{[1
]}

机构：

[1] Texas A&M Univ, Analog & Mixed Signal Ctr, Dept Elect Engn, College Stn, TX 77840 USA

来源：

PROCEEDINGS OF THE IEEE 2003 CUSTOM INTEGRATED CIRCUITS CONFERENCE | 2003年

关键词：

D O I：

10.1109/CICC.2003.1249374

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

An OTA with a feedforward compensation scheme uses positive phase shift of Left Half plane (LHP) zeros created by a feedforward path to cancel the negative phase shift of poles, thereby overcoming the limitations of traditional Miller compensation schemes. The OTA is used in the design of a fourth order switched capacitor bandpass SigmaDelta modulator with the IF at one-fourth of the sampling frequency. The modulator uses cascade of resonators in feedback architecture, along with feedforward paths for stability. Experimental results for the bandpass modulator designed in TSMC 0.35 mum CMOS technology show a peak SNR of 80 dB and 54 dB for 270 kHz and 3.84 MHz bandwidth at 92 MHz clock and consumes 19 mA from a +/-1.25 V supply. The OTA has a DC gain of 80 dB, 1.4 GHz GBW, phase margin of 62degrees and 2ns settling time for 2pF load capacitor.

引用

页码：123 / 126

页数：4