ADS1218_14 Datasheet, PDF (12/45 Pages) Texas Instruments – 8-Channel, 24-Bit ANALOG-TO-DIGITAL CONVERTER with FLASH Memory

ADS1218
SBAS187C – SEPTEMBER 2001 – REVISED SEPTEMBER 2005
www.ti.com
TYPICAL CHARACTERISTICS (continued)
AV_DD = +5V, DV_DD = +5V, f_OSC = 2.4576MHz, PGA = 1, R_DAC = 150kΩ, V_REF ≡ (REF IN+) – (REF IN–) = +2.5V, and
f_DATA = 10Hz, unless otherwise specified.
22
21
20
19
18
17
16
15
14
13
12
0
EFFECTIVE NUMBER OF BITS
vs DECIMATION RATIO
PGA1 PGA2 PGA4 PGA8
PGA32
PGA16
PGA64
PGA128
Sinc² Filter
500
1000
1500
Decimation Ratio = ^fMOD
f_DATA
Figure 5.
2000
FAST SETTLING FILTER
EFFECTIVE NUMBER OF BITS vs DECIMATION RATIO
22
21
20
19
18
17
16
15
14
Fast Settling Filter
13
12
0
500
1000
1500
Decimation Ratio = ^fMOD
f_DATA
2000
Figure 6.
NOISE vs INPUT SIGNAL
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
−2.5
−1.5
−0.5
0.5
1.5
2.5
V_IN (V)
Figure 7.
130
120
110
100
90
80
70
60
50
40
30
20
10
0
1
CMRR vs FREQUENCY
10
100
1k
10k
Frequency of CM Signal (Hz)
Figure 8.
100k
120
110
100
90
80
70
60
50
40
30
20
10
0
1
PSRR vs FREQUENCY
10
100
1k
10k
Frequency of Power Supply (Hz)
Figure 9.
100k
OFFSET vs TEMPERATURE
50
PGA1
PGA16
0
−50
−100
−150
PGA64
PGA128
−200
−50 −30 −10 10
30
50
70
90
Temperature (_C)
Figure 10.
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