The advantages of employing chopper stabilization for the implementation of IAs are high CMRR
, high accuracy, low drift, suppression of low-frequency noise with low signal aliasing and can achieve rail-to-rail input operation .
In the proposed scheme, the implementation requires matched resistor pair; however, it is shown that high CMRR
can be achieved by 1 % matching ratio of the resistors.
Supply voltage Gain PM GM BW 1.8 V 103 dB 49[degrees] 11.46 dB 12.4 KHz degree Supply voltage SR [ICMR.sup.-] [ICMR.sup.+] CMRR
1.8 V 151.50 V/ 71.45 mV 1.60 mV 71.27 dB [micro]S Supply voltage [PSRR.sup.+] [PSRR.sup.-] Offset Pd 1.8 V 73.60 dB 81.75 dB 11.30 mV 316.24 [micro]W Table 2: Performance summary of the comparator.
The device has a common-mode rejection ratio (CMRR
) >80 dB, with sampling frequency configured at 2000 Hz and the signal was filtered between 20 and 500 Hz.
Though this topology can achieve common-mode rejection (CMRR
) above 80 dB at DC, the CMRR
dramatically degrades as frequency increases.
To achieve this, we used a INA128 biomedical instrumentation amplifier manufactured from Texas Instruments[R], which has a CMRR
of 120 dB, necessary to acquire such signals.
(b) With sinusoid signals, 20 dB/decade frequency roll-off had been observed at 3.3 MHz onwards; measured CMRR
[approximately equal to] 57 dB at [V.sub.2] = [-V.sub.1]
(1) Service of Neurology and CMRR
, Neuropsychology Unit, University Hospital of Strasbourg, 1 avenue Moliere, 67000 Strasbourg, France
He retired in July 2006 to become director of cmrr
. He received a bachelor's degree from SHSU in criminology and corrections and his Master of Public Administration with a criminal justice concentration from Texas A&M Corpus Christi.