Page 302 - Mechatronics with Experiments

JWST499-Cetinkunt
JWST499-c05
288 MECHATRONICS Printer: Yet to Come October 28, 2014 11:15 254mm×178mm
Shield
Sources 1-16 Multiplexer ADC conversion
Ch 1 Ch 1 (sample and hold)
+
Ch 2
-
GND Ch 3 V
out
Ch 2
+
Ch 16
-
GND

Ch 16
+
16-Channel ADC
-
GND
(a)

Shield 16-Channel ADC
Sources 1-8 Multiplexer
Ch 1-H Ch 1-H
+
Ch 1-L Ch 2-H
-
GND
Ch 2-H ADC Conversion
+
Ch 2-L Ch 8-H
-
GND Multiplexer V
Ch 1-L out
Ch 2-L
Ch 8-H
+
Ch 8-L Ch 8-L
-
GND

(b)
FIGURE 5.27: (a) and (b) show the use of an 16-channel analog to digital converter (ADC) on a
data acquisition system for sampling a set of 16-channel single-ended signals and 8-channel
differential-ended signals.

The performance characteristics of a differential amplifier are defined by the differ-
ential gain, common mode gain, and common-mode rejection ratio (CMMR),
V out1 − V out2
K diff = (5.192)
V in1 − V in2
V out1 − V out2
K = (5.193)
cm
((V + V )∕2)
in1 in2
K diff
CMRR = (5.194)
K
cm