Title
A third-order DT ΔΣ modulator using noise-shaped bidirectional single-slope quantizer
Abstract
In this paper, a prototype delta-sigma ADC is implemented in a 0.18μm 2P5M CMOS process. The input signal sampling capacitors are shared with the front-end DAC capacitors. The sampling frequency is 50MHz and oversampling ratio is 24. The out-of-band peaking is deliberately set to help the stability and to allow larger input signals to be processed by the loop. This modulator achieves 78.2dB peak SNDR and 79.3dB peak SNR while consuming 1.35mW analog and 1.55mW digital power from 1.5V supplies. The major portion of the digital power (1.3mW) is consumed by an overdesigned generic clock generator to provide flexibility in testing with various sampling frequencies. The rest of the digital power (0.25mW) includes the DLL, digital counter, DWA and the comparator. The achieved minimal analog power is the direct result of the extra order of noise shaping, and the elimination of the flash ADC and the typical large capacitive loading that comes with it. The FoM is 210fJ/conversion-step and it can easily be reduced further with redesign (i.e., eliminating the wasted clock generator power).
Year
DOI
Venue
2011
10.1109/ISSCC.2011.5746403
Solid-State Circuits Conference Digest of Technical Papers
Keywords
Field
DocType
CMOS integrated circuits,analogue-digital conversion,capacitors,delta-sigma modulation,2P5M CMOS process,DLL,DWA,clock generator,delta-sigma ADC,digital counter,frequency 50 MHz,front-end DAC capacitors,input signal sampling capacitors,noise-shaped bidirectional single-slope quantizer,out-of-band peaking,power 0.25 mW,power 1.35 mW,power 1.55 mW,size 0.18 mum,third-order DT ΔΣ modulator,voltage 1.5 V
Computer science,Third order,Signal-to-noise ratio,Delta-sigma modulation,CMOS,Electronic engineering,Flash ADC,Voltage-controlled oscillator,Noise shaping,Quantization (signal processing),Electrical engineering
Journal
Volume
Issue
ISSN
46
12
0193-6530
ISBN
Citations 
PageRank 
978-1-61284-303-2
3
0.59
References 
Authors
3
2
Name
Order
Citations
PageRank
nima maghari18219.11
Un-Ku Moon2836140.98