The quantization noise leakage of the first stage in a MASH21 sigma-delta modulator is analyzed. The results show that the finite DC gain of the opamp is the main reason for noise leakage, and finite GBW and SR only generate harmonic distortion. The relationship between DC gain and leakage is modeled and conclusions on design criteria are reached. As an example, a MASH21 modulator for a digital audio application is realized. This modulator, fabricated in an 0.18 μm mixed signal process, achieves an SNDR of 91 dB with 1.8 V supply, which verifies the analysis and design criteria.
参考文献
| [1] | Northworthy S R,Schreier R,Temes G.Delta sigma data converters:theory,design,and simulation.IEEE Press,1997 |
| [2] | Schreier R,Temes G.Understanding delta sigma data converters.IEEE Press,2005 |
| [3] | Rio R D,Medeiro F,Perez-verdu B,et al.CMOS cascode sigma-delta modulators for sensors and telecom.Springer,2006 |
| [4] | Coban A L.A low voltage high-resolution delta-sigma modulators.PhD Thesis,Georgia Institute of Technology,1998 |
| [5] | Yang W,Schofield W,Shibata H,et al.A 100 mW 10 MHz-BW CT △∑ modulator with 87 dB DR and 91 dBc IMD.ISSCC Dig Tech Papers,2008:498 |
| [6] | Matsuya Y,Uchimura K,Iwata A,et al.A 16-bit oversampling A-to-D conversion technology using triple-integration noise shaping.IEEE J Solid-State Circuits,1987,22:921 |
| [7] | Williams L A Ⅲ.Modeling and design of high resolution sigma delta modulators.PhD Thesis,Stanford University,1993 |
| [8] | Rabbi S.Design of low voltage low power sigma delta modulators.PhD Thesis,Stanford University,1998 |
| [9] | Feldman A R.High-speed,low-power sigma-delta modulators for RF baseband channel applications.PhD Thesis,University of California,Berkeley,1998 |
| [10] | Johns D A,Martin K.Analog integrated circuit design.John Wiley & Sons Inc,1997 |
| [11] | TSMC18MMRF datasheet |
| [12] | Sansen W,Qiuting H,Halonen K A.Transient analysis of charge transfer in SC filter error and distortion.IEEE J Solid-State Circuits,1987,SC-22(2):268 |
| [13] | Ruiz-Amaya J,de la Rosa J M,Fernandez F V,et al.High-level synthesis of switched-capacitor,switched-current and continuous-time △∑ modulators using Simulink based time domain behavioral models.IEEE Trans Circuits Syst,2005,52(13):1795 |
| [14] | Williams L A Ⅲ,Wooley B A.A third-order sigma-delta modulator with extended dynamic range.IEEE J Solid-State Circuits,1994,29(6):193 |
| [15] | Allen P E,Holberg D R.CMOS analog circuit design.2nd ed.Oxford University Press,2002 |
| [16] | Razavi B.Design of analog CMOS integrated circuits.McGraw-Hill,2001 |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%