A 630μW zero-crossing-based ΔΣ ADC using switched-resistor current sources in 45nm CMOS

A delta-sigma analog-to-digital converter employs zero-crossing-based integrators to achieve low power operation at 50 MHz sampling rate. Switched resistors, used as current sources, provide good dynamic current matching, eliminating the need for common-mode feedback circuits. The effect of the swit...

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Bibliographic Details
Published in2009 IEEE Custom Integrated Circuits Conference pp. 1 - 4
Main Authors Musah, T., Sunwoo Kwon, Lakdawala, H., Soumyanath, K., Un-Ku Moon
Format Conference Proceeding
LanguageEnglish
Published IEEE 01.09.2009
Subjects
Analog-digital conversion
Circuit testing
Feedback circuits
Linearity
Resistors
Sampling methods
Switching circuits
Voltage
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Summary:A delta-sigma analog-to-digital converter employs zero-crossing-based integrators to achieve low power operation at 50 MHz sampling rate. Switched resistors, used as current sources, provide good dynamic current matching, eliminating the need for common-mode feedback circuits. The effect of the switched resistors on the linearity of the zero-crossing-based integrator is discussed. Also, a unidirectional 2-phase charging scheme is proposed to improve input signal swing and reduce overshoot voltage. Test chip implemented in a 45 nm LP digital CMOS achieves 54.3 dB DR, 52.5 dB SNR, and 47.7 dB SNDR at 0.833 MHz input while dissipating 630 muW from a 1.1 V supply.
ISBN:1424440718
9781424440719
ISSN:0886-5930
2152-3630
DOI:10.1109/CICC.2009.5280909