Finite GBW compensation technique for CT ΔΣ modulators with differentiator based ELD compensation

Author

Chao Chu ; Anders, Jens ; Becker, Joachim ; Ortmanns, Maurits

Author_Institution

Inst. of Microelectron., Univ. of Ulm, Ulm, Germany

fYear

2015

fDate

7-10 June 2015

Firstpage

1

Lastpage

4

Abstract

In this work, the mixed-signal differentiator technique for the compensation of excess loop delay has been extended to counteract the effect of the finite GBW of the amplifiers. A RZ DAC is utilized to realize a fast compensation path from the quantizer output to the input of the last integrator. After proper tuning of the scaling coefficients, the original NTF of the modulator can be restored, which has been verified in a 3^rd order, single-bit single-loop CT ΔΣ modulator. By using the modified compensation technique, the GBW requirements on the amplifiers can be relaxed significantly while maintaining the SQNR performance and the modulator stability. Consequently, the power consumption of the amplifiers can be drastically reduced.

Keywords

amplifiers; delta-sigma modulation; low-power electronics; mixed analogue-digital integrated circuits; ELD compensation; RZ DAC; amplifiers; continuous-time ΔΣ modulator; excess loop delay compensation; finite GBW compensation; gain bandwidth product; mixed-signal differentiator; modulator stability; power consumption; quantizer output; return-to-zero digital-to-analog converter; scaling coefficients; single-bit single-loop CT ΔΣ modulator; Bandwidth; Clocks; Computed tomography; Delays; Modulation; Noise; Optical signal processing;

fLanguage

English

Publisher

ieee

Conference_Titel

New Circuits and Systems Conference (NEWCAS), 2015 IEEE 13th International

Conference_Location

Grenoble

Type

conf

DOI

10.1109/NEWCAS.2015.7182112

Filename

7182112