ADS7870_14 Datasheet, PDF (8/45 Pages) Texas Instruments – 12-BIT, 52-kSPS, DATA ACQUISITION SYSTEM WITH ANALOG-TO-DIGITAL CONVERTER, MUX, PGA, AND REFERENCE

ADS7870
SBAS124C − DECEMBER 1999 − REVISED DECEMBER 2005
OUTPUT OFFSET ERROR
vs
COMMON-MODE VOLTAGE
2
1.5
1
Gain = 10 ^{Gain = 1}
0.5
0
−0.5
Gain = 20
−1
−1.5
1 LSB =
−72 dB for Gain = 1,
−98 dB for Gain = 20
−2
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Common-Mode Voltage − V
Figure 5
QUIESCENT CURRENT
vs
SAMPLING RATE
1.4
VREF and Buffer ON, Oscillator OFF
Serial Data Clocked During the 48 Clock
1.2 ^{Count Conversion Cycle, CCLK = SCLK}
1
VDD = 5 V
0.8
VDD = 3 V
0.6
0.4
0.2
0
1
10
100
Sampling Rate − ksps
Figure 7
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OUTPUT OFFSET ERROR
vs
POWER SUPPLY VOLTAGE
8
50 Ksps, CCLK = 2.5 MHz,
7
Gain = 20 ^{VREF = 2.048 V}
Gain = 10
6
5
4
3
Gain = 1
2
1
4 LSB =
0
86 dB for Gain = 20,
60 dB for Gain = 1
−1
2 2.5 3 3.5 4 4.5 5
VDD − Supply Voltage − V
Figure 6
5.5 6
PEAK-TO-PEAK OUTPUT NOISE
vs
GAIN
6
5
4
3
2
1
0
1 2 4 5 8 10 16 20
Gain
Figure 8
8