A 21 nV/root Hz Chopper-Stabilized Multi-Path Current-Feedback Instrumentation Amplifier With 2 mu V Offset

作者：Fan Qinwen^*; Huijsing Johan H; Makinwa Kofi A A

来源：IEEE Journal of Solid-State Circuits, 2012, 47(2): 464-475.

DOI：10.1109/JSSC.2011.2175269

• Chopping
• current feedback
• high power efficiency
• low offset
• multi-path
• offset-stabilization
• precision amplifier
• ripple reduction
• sensor readout

This paper describes the design of a precision instrumentation amplifier. It employs chopping to reduce its offset and 1/f noise, and the resulting ripple caused by the up-modulated offset and 1/f noise is suppressed by a ripple reduction loop. A multi-path architecture is used to eliminate the transfer function notch that would otherwise be introduced by the ripple reduction loop. The amplifier is implemented in a standard 0.7 mu m CMOS technology and draws 143 mu A current from a 5 V supply. Its input-referred noise is 21 nV/root Hz and its residual offset is less than 2 mu V (12 samples). The instrumentation amplifier can also be configured as a general-purpose opamp with half the noise and offset, but which dissipates the same amount of power.

• 出版日期2012-2