Abstract
This paper describes a third-order sigma-delta (∑Δ) modulator that is designed and implemented in 0.18-μm CMOS process. In order to increase the dynamic range, this modulator takes advantage of mixed-mode integrators that consist of analog and digital integrators. A calibration technique is applied to the digital integrator to mitigate mismatch between analog and digital paths. It is shown that the presented modulator architecture can achieve a 12-dB better dynamic range than conventional structures with the same oversampling ratio (OSR). The experimental prototype chip achieves a 76-dB dynamic range for a 200-kHz signal bandwidth and a 55-dB dynamic range for a 5-MHz signal bandwidth. It dissipates 4 mW from 1.8-V supply voltages and occupies 0.7-mm2 silicon area.
Original language | English |
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Pages (from-to) | 918-925 |
Number of pages | 8 |
Journal | IEEE Journal of Solid-State Circuits |
Volume | 40 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2005 |
Keywords
- Analog-digital conversion
- Calibration
- Sigmadelta modulation