Datasheet

MAX11120–MAX11128
1Msps, Low-Power, Serial 12-/10-/8-Bit,
4-/8-/16-Channel ADCs
31Maxim Integrated
Table 8. Analog Input Configuration and Unipolar/Bipolar Waveforms
Table 9. ADC Output as a Function of Unipolar/Bipolar Register Settings
CHANNEL SELECTION UNIPOLAR REGISTER BIPOLAR REGISTER
FUNCTION
BIT NAME UCH0/1 PDIFF_COM BCH0/1
AIN0 Selection:
CHSEL[3:0] = 0000
CHSCAN0 = 1
0 0 0 AIN0 (binary, unipolar)
0 0 1 AIN0/1 pair (two’s complement, bipolar)
1 0 0 AIN0/1 pair (binary, unipolar)
1 0 1
AIN0/1 pair (binary, unipolar); Unipolar register
takes precedence
X 1 X AIN0 referred to REF-/AIN15 (binary, unipolar)
AIN1 Selection:
CHSEL[3:0] = 0001
CHSCAN1 = 1
0 0 0 AIN1 (binary, unipolar)
0 0 1 AIN0/1 pair (two’s complement, bipolar)
1 0 0 AIN0/1 pair (binary, unipolar)
1 0 1
AIN0/1 pair (binary, unipolar), Unipolar register
takes precedence
X 1 X AIN1 referred to REF-/AIN15 (binary, unipolar)
ANALOG INPUT
CONFIGURATION
SUPPORTED WAVEFORMS
UNIPOLAR/BIPOLAR
REGISTER SETTING
REFSEL = 0 REFSEL = 1
Single-
Ended
Unipolar
(Binary
Coding)
Table 10. Unipolar Register:
Set desired channel(s) to 0
or PDIFF_COM to 1.
Counterpart Register
Table 11. Bipolar Register:
Set desired channel(s) to 0.
Fully
Differential
Unipolar
(Binary
Coding)
Table 10. Unipolar Register:
Set desired channel(s) to 1.
Counterpart Register
Table 11. Bipolar Register:
Set desired channel(s) to 0.
Fully
Differential
Bipolar
(2’s Comp)
See Table 11. Bipolar
Register:
Set desired channel(s) to 1.
Counterpart Register
Table 10. Unipolar Register:
Set desired channel(s) to 0.
REF+
REF+
2
REF-
V
IN+
V
IN-
V
IN-
GND
REF+
RANGE: 1V - V
DD
REF+
RANGE: 1V - V
DD
1V
0V
-0.3V
REF+
V
IN+
V
FS
= REF+
RANGE = 0
V
FS
= 2REF+
RANGE = 1
V
FS
= REF+
RANGE = 0
V
FS
= 2REF+
RANGE = 1
REF+
REF-
V
IN+
GND, AIN15
PDIFF_COM = 1
REF+
RANGE: 1V - V
DD
REF+
RANGE: 1V - V
DD
1V
0V
-0.3V
REF+
V
IN+
REF+
REF-
V
IN+
V
IN-
V
IN-
GND
REF+
RANGE: 1V - V
DD
REF+
RANGE: 1V - V
DD
1V
0V
-0.3V
REF+
V
IN+
V
IN-
(DC OFFSET
OR
SINUSOID)
V
IN-
(DC OFFSET
OR
SINUSOID)