Name
Title | ||
|---|---|---|
A 75 dB SNDR 10-MHz Signal Bandwidth Gm-C-Based Sigma-Delta Modulator With a Nonlinear Feedback Compensation Technique |
Abstract | ||
|---|---|---|
Wideband ( ≥10 MHz) continuous-time (CT) sigma-delta (ΣΔ) modulators generally use active-RC filters. On the other hand, Gm-C-filters avoid the need of a power-hungry driving stage due to their small loading. At the moment, the major challenge for designing Gm-C-based ΣΔ modulator is the narrow linear input range due to the nonlinear Gm amplifier, which leads to low SNDR. This work develops a nonlinearity compensation technique for Gm-C-based ΣΔ modulator. This technique designs a nonlinear feedback DAC which has matched V-I transfer curve as the first Gm amplifier (Gm1). As a result, the distortions of Gm1 are significantly suppressed at the modulator output. This method is prototyped in a 640 MS/s Gm-C-based ΣΔ modulator with 10 MHz signal bandwidth in a 0.18- μm CMOS process. With this technique, the linear input range of the modulator is greatly enlarged. Consequently, the peak SNDR of the modulator is improved by about 8 dB to 75 dB. This >12-bit ENOB is achieved for the first time for wide-band Gm-C-based ΣΔ modulators. |
Year | DOI | Venue |
|---|---|---|
2015 | 10.1109/TCSI.2015.2452333 | IEEE Transactions on Circuits and Systems |
Keywords | Field | DocType |
Analog-to-digital converter, continuous-time sigma-delta modulator, Gm-C filter, nonlinearity compensation | Wideband,Control theory,Linearity,Effective number of bits,Delta-sigma modulation,Electronic engineering,Modulation,Sigma,Nonlinear distortion,Mathematics,Amplifier | Journal |
Volume | Issue | ISSN |
62 | 9 | 1549-8328 |
Citations | PageRank | References |
2 | 0.46 | 25 |
Authors | ||
3 | ||
Name | Order | Citations | PageRank |
|---|---|---|---|
| Jiageng Huang | 1 | 4 | 1.52 |
| Shiliang Yang | 2 | 5 | 1.25 |
| George Jie Yuan | 3 | 174 | 22.14 |