Datasheet

MAX1302
Differential Common-Mode Range
The MAX1302 differential common-mode range
(V
CMDR
) must remain within -4.75V to +5.5V to obtain
valid conversion results. The differential common-mode
range is defined as:
In addition to the common-mode input voltage limita-
tions, each individual analog input must be limited to
±6V with respect to AGND1.
The range-select bits R[2:0] in the analog input config-
uration bytes determine the full-scale range for the cor-
responding channel (Tables 2 and 6). Figures 9, 10,
and 11 show the valid analog input voltage ranges for
the MAX1302 when operating with FSR = V
REF
/2, FSR
= V
REF
, and FSR = 2 x V
REF
, respectively. The shaded
area contains the valid common-mode voltage ranges
that support the entire FSR.
V
CH CH
CMDR
_ _
=
+
()
+
()
−
2
8-Channel, ±V
REF
Multirange Inputs,
Serial 16-Bit ADC
18 ______________________________________________________________________________________
Table 3. Input Data Word Formats
DATA BIT
OPERATION
D7
(START)
D6 D5 D4 D3 D2 D1 D0
Conversion-Start Byte
(Tables 4 and 5)
1C2C1C00 0 0 0
Analog-Input Configuration Byte
(Table 2)
1 C2 C1 C0 DIF/SGL R2 R1 R0
Mode-Control Byte
(Table 7)
1M2M1M01 0 0 0
Table 4. Channel Selection in Single-Ended Mode (DIF/SGL = 0)
CHANNEL-SELECT BIT CHANNEL
C2 C1 C0 CH0 CH1 CH2 CH3 CH4 CH5 CH6 CH7 AGND1
000+ -
001 + -
010 + -
011 + -
100 + -
101 + -
110 +-
111 +-
Table 5. Channel Selection in True-Differential Mode (DIF/SGL = 1)
CHANNEL-SELECT BIT CHANNEL
C2 C1 C0 CH0 CH1 CH2 CH3 CH4 CH5 CH6 CH7 AGND1
000+-
0 0 1 RESERVED
010 +-
0 1 1 RESERVED
100 +-
1 0 1 RESERVED
110 +-
1 1 1 RESERVED