Datasheet

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SBAS317E − APRIL 2004 − REVISED MAY 2006
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12
TYPICAL CHARACTERISTICS: MSC1200 AND MSC1201 ONLY (Continued)
AV
DD
= +5V, DV
DD
= +5V, f
OSC
= 8MHz, PGA = 1, f
MOD
= 15.625kHz, ADC Bipolar Mode, Buffer ON, and V
REF
≡ (REF IN+) − (REF IN−) = +2.5V, unless
otherwise specified.
20
19
18
17
16
15
14
13
12
11
10
FAST SETTLING FILTER
EFFECTIVE NUMBER OF BITS vs DECIMATION RATIO
0 500 1000
Gain 1
Gain 16
Gain 128
1500 2000
ENOB
1500
Decimation Value
EFFECTIVE NUMBER OF BITS vs f
MOD
(set with ACLK)
25
20
15
10
5
0
ENOB (rms)
Data Rate (SPS)
1 10 100 1k 10k 100k
f
MOD
= 15.6kHz
f
MOD
= 62.5kHz
f
MOD
= 203kHz
f
MOD
= 110kHz
f
MOD
= 31.25kHz
EFFECTIVE NUMBER OF BITS vs f
MOD
(set with ACLK)
WITH FIXED DECIMATION
25
20
15
10
5
0
ENOB (rms)
Data Rate (SPS)
10 100 1k 10k 100k
DEC = 2020
DEC = 255
DEC = 500
DEC = 50
DEC = 20
DEC = 10
4500
4000
3500
3000
2500
2000
1500
1000
500
0
HISTOGRAM OF ADC OUTPUT DATA
ppm of FS
−
2
Number of Occurrences
−
1.5
−
1
−
0.5 0 0.5 1 1.5 2
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
NOISE vs INPUT SIGNAL
V
IN
(V)
−
2.5
−
1.5 0.5
−
0.5 1.5 2.5
Noise (rms, ppm of FS)
22.0
21.5
21.0
20.5
20.0
19.5
19.0
18.5
18.0
EFFECTIVE NUMBER OF BITS vs INPUT SIGNAL
(Internal and External V
REF
)
V
IN
(V)
−
2.5
−
1.5 0.5
−
0.5 1.5 2.5
ENOB (rms)
External
Internal