MAX195 Maxim, MAX195 Datasheet - Page 12

• Manufacturer Part Number: MAX195
• Description: 16-Bit / 85ksps ADC with 10A Shutdown
• Manufacturer: Maxim

be improved by trimming, but the drift is too great to
provide good stability over temperature. The MAX427
buffer provides the necessary drive current to stabilize
the REF input quickly after capacitance changes.
The reference inaccuracies contribute additional full-
scale error. A reference with less than
(15 parts per million) over the operating temperature
range is required to limit the additional error to less
than 1LSB. The MAX6241 achieves a drift specification
16-Bit, 85ksps ADC with 10µA Shutdown
Figure 10. Typical Reference Circuit for AC Accuracy
Figure 11. High-Accuracy Reference
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0.1 F
MAX874
V
IN
+15V
GND
V
IN
8V
2.2 F
4
2
COMP
V
OUT
8
6
1 F
1000pF
4.096V
3
0.1 F
NR
2
3
MAX6241
MAX427
1
-15V
⁄
GND
2
IN
16
2
4
7
4
total error
TRIM
OUT
2k
0.1 F
0.1 F
6
5
6
1k
0.1 F
10
10k
of 1ppm/°C (typ). This allows reasonable temperature
changes with less than 1LSB error. While the
MAX6241’s initial-accuracy specification (0.02%)
results in an offset error of about ±14LSB, the reference
voltage can be trimmed or the offset can be corrected
in software if absolute DC accuracy is essential. Figure
11’s circuit provides outstanding temperature stability
and also provides excellent DC accuracy if the initial
error is corrected.
LOW ESR
47 F
2.2 F
0.1 F
0.1 F
1N914
12
1N914
REF
10
MAX195
12
AGND
14
REF
VSSA
-5V
15
MAX195
VDDA
AGND
+5V
16
14