This paper presents a CMOS chopper instrumentation amplifier with a switched-capacitor band-pass filter. The switched-capacitor band-pass filter is employed to improve the matching between the chopping frequency and the center frequency of the band-pass filter, resulting in higher CMRR and lower offset. The combination of the band-pass filter and the peak-signal sampling approach eliminates the need for the anti-aliasing filter of the subsequent ADC and allows the sampling rate of the ADC to be reduced by a factor of 16 with minimal increase in high-frequency aliased noise. The prototype chip is fabricated in a 0.7 /spl mu/m CMOS process and has an overall gain of 60.6 dB with a 5.5 kHz bandwidth and a minimum in-band CMRR of 137 dB. The input-referred noise and input offset are 17.2 nV//spl radic/(Hz) and 88.7 /spl mu/V respectively. The amplifier power consumption is 11 mW at a supply voltage of 5 V.
[1]
Qiuting Huang,et al.
A fully integrated, untrimmed CMOS instrumentation amplifier with submicrovolt offset
,
1999
.
[2]
Gabor C. Temes,et al.
Circuit techniques for reducing the effects of op-amp imperfections: autozeroing, correlated double sampling, and chopper stabilization
,
1996,
Proc. IEEE.
[3]
E. Vittoz,et al.
A CMOS Chopper Amplifier
,
1986,
ESSCIRC '86: Twelfth European Solid-State Circuits Conference.
[4]
G. Temes,et al.
Analog MOS Integrated Circuits for Signal Processing
,
1986
.
[5]
Qiuting Huang,et al.
A low-noise CMOS instrumentation amplifier for thermoelectric infrared detectors
,
1997
.