TY - GEN

T1 - A high power efficiency class AB switched-opamp for low voltage low power sigma-delta modulators

AU - Wang, Hanging

AU - Xu, Jian

AU - Wu, Xiaobo

PY - 2009/12/1

Y1 - 2009/12/1

N2 - Two-stage Class-A switched-opamp (SO) is the most popular module in previous low voltage low power SO sigma-delta modulators (SDM). The SO saves about 30%∼40% of the total power since its output stage is just turned off at the integrating phase. To further increase efficiency a novel high power efficiency class AB current mirror SO is proposed in this paper. By turning off the entire SO together with its common mode feedback (CMFB) circuit, the power consumption of the SO can be reduced by 50%. A Class-AB load-compensated opamp version improves the power efficiency further. The proposed SO was fabricated in a 0.35μm TSMC CMOS standard process and achieved a DC gain of 62.7dB, a GBW of 4.39MHz and a slew rate of 1.2V/μs when the load capacitor is 10pF. The effective power consumption including the CMFB circuit is 6.6μW under 1.5V supply voltage. The simulation results showed that the proposed SO can be applied to low power low voltage SDM with a sampling frequency of less than 0.5MHz.

AB - Two-stage Class-A switched-opamp (SO) is the most popular module in previous low voltage low power SO sigma-delta modulators (SDM). The SO saves about 30%∼40% of the total power since its output stage is just turned off at the integrating phase. To further increase efficiency a novel high power efficiency class AB current mirror SO is proposed in this paper. By turning off the entire SO together with its common mode feedback (CMFB) circuit, the power consumption of the SO can be reduced by 50%. A Class-AB load-compensated opamp version improves the power efficiency further. The proposed SO was fabricated in a 0.35μm TSMC CMOS standard process and achieved a DC gain of 62.7dB, a GBW of 4.39MHz and a slew rate of 1.2V/μs when the load capacitor is 10pF. The effective power consumption including the CMFB circuit is 6.6μW under 1.5V supply voltage. The simulation results showed that the proposed SO can be applied to low power low voltage SDM with a sampling frequency of less than 0.5MHz.

KW - Common mode feedback circuit (CMFB)

KW - Sigma-delta modulator (SDM)

KW - Switched opamp (SO)

UR - http://www.scopus.com/inward/record.url?scp=77949757631&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77949757631&partnerID=8YFLogxK

U2 - 10.1109/EDSSC.2009.5394224

DO - 10.1109/EDSSC.2009.5394224

M3 - Conference contribution

AN - SCOPUS:77949757631

SN - 9781424442980

T3 - 2009 IEEE International Conference on Electron Devices and Solid-State Circuits, EDSSC 2009

SP - 429

EP - 432

BT - 2009 IEEE International Conference on Electron Devices and Solid-State Circuits, EDSSC 2009

T2 - 2009 IEEE International Conference on Electron Devices and Solid-State Circuits, EDSSC 2009

Y2 - 25 December 2009 through 27 December 2009

ER -