MAX11120–MAX11128
1Msps, Low-Power, Serial 12-/10-/8-Bit,
4-/8-/16-Channel ADCs
U Initial voltage accuracy
Choosing a Reference
For devices using an external reference, the choice of the
reference determines the output accuracy of the ADC.
An ideal voltage reference provides a perfect initial accu-
racy and maintains the reference voltage independent
of changes in load current, temperature, and time. The
following parameters need to be considered in selecting
a reference:
U Temperature drift
U Current source capability
U Current sink capability
U Quiescent current
U Noise. The MAX6033 and MAX6043 are also excellent
reference choices (Figure 13).
+5V
0.1µF
10µF
V
DD
V
OVDD
100pF
V
DD
OVDD
0.1µF
10µF
0.1µF
10µF
500I
AGND
500I
4
3
5
INPUT 1
MAX11120–MAX11128
AIN0
10I
1
MAX4430
470pF
470pF
COG
CAPACITOR
V
DC
SCLK
DOUT
SCLK
2
-5V
10µF
MISO
CPU
AIN1
0.1µF
+5V
COG
CAPACITOR
INPUT 2
CS
SS
AIN15
REF
MOSI
DIN
GND
10µF
0.1µF
10µF
+5V
100pF
7
6
2
1
OUTF
OUTS
IN
1µF
0.1µF
500I
MAX6126
0.1µF
500I
4
3
4
3
5
GNDS
GND
NR
INPUT 2
10I
0.1µF
1
MAX4430
V
DC
2
-5V
10µF
0.1µF
Figure 13. Typical Application Circuit
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