Datasheet

MAX11120–MAX11128
1Msps, Low-Power, Serial 12-/10-/8-Bit,
4-/8-/16-Channel ADCs
37Maxim Integrated
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 indepen dent
of changes in load current, temperature, and time. The
following parameters need to be considered in selecting
a reference:
U Initial voltage accuracy
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).
Figure 13. Typical Application Circuit
MAX4430
MAX11120–MAX11128
MAX6126
MAX4430
+5V
CPU
SCLK
MISO
MOSI
SS
INPUT 1
4
3
2
5
1
V
DC
100pF
500I
-5V
500I
10I
0.1µF 10µF
0.1µF 10µF
0.1µF
470pF
470pF
10µF
INPUT 2
COG
CAPACITOR
COG
CAPACITOR
0.1µF 10µF
1µF 0.1µF
+5V
0.1µF
V
DD
V
DD
AGND
AIN0
AIN1
AIN15
REF
OUTF
OUTS
GNDS
1
27
6
4
3
GND
DIN
IN
NR
CS
DOUT
SCLK
OVDD
GND
V
OVDD
0.1µF 10µF
+5V
INPUT 2
4
3
2
5
1
V
DC
100pF
500I
-5V
500I
10I
0.1µF 10µF
0.1µF 10µF