LTC1289 Linear Technology, LTC1289 Datasheet - Page 10

• Manufacturer Part Number: LTC1289
• Description: 3 Volt Single Chip 12-Bit Data Acquisition System
• Manufacturer: Linear Technology

LTC1289
A
MUX Address
The first four bits of the input word assign the MUX
configuration for the requested conversion. For a given
channel selection, the converter will measure the voltage
between the two channels indicated by the + and – signs
in the selected row of Table 1. Note that in differential
10
Table 1. Multiplexer Channel Selection
SGL/
DIFF
PPLICATI
0
0
0
0
0
0
0
0
MUX ADDRESS
SIGN
ODD
0
0
0
0
1
1
1
1
SELECT
1 0
0 0
0 1
1 0
1 1
0 0
0 1
1 0
1 1
CHANNEL
0,1
2,3
4,5
6,7
{
{
{
{
O
U
0
+
–
4 Differential
+
–
+
–
+
–
+
–
S
DIFFERENTIAL CHANNEL SELECTION
(
(
(
(
(
(
(
(
–
+
–
+
–
+
–
+
1
–
+
)
)
)
)
)
)
)
)
I FOR ATIO
U
4,5
6,7
+
–
2
{
{
Figure 1. Examples of Multiplexer Options on the LTC1289
1ST CONVERSION
3
–
+
+
–
+
–
COM (UNUSED)
W
Changing the MUX Assignment “On the Fly”
4
+
–
CHANNEL
5
–
+
U
0
1
2
3
4
5
6
7
+
–
6
8 Single-Ended
+
+
+
+
+
+
+
+
COM (
7
–
+
–
)
SGL/
DIFF
mode (SGL/DIFF = 0) measurements are limited to four
adjacent input pairs with either polarity. In single-ended
mode, all input channels are measured with respect to
COM.
1
1
1
1
1
1
1
1
MUX ADDRESS
5,4
6
7
{
{
SIGN
ODD
0
0
0
0
1
1
1
1
2ND CONVERSION
COM (
SELECT
–
+
+
+
1 0
0
0
1
1
0
0
1
1
–
Combinations of Differential and Single-Ended
0
1
0
1
0
1
0
1
)
0
+
CHANNEL
0,1
2,3
SINGLE-ENDED CHANNEL SELECTION
4
5
6
7
{
{
+
1
2
+
+
–
–
+
+
+
+
+
COM (
3
+
–
)
4
+
+
5
+
6
LTC1289 AIF01
+
7
COM
–
–
–
–
–
–
–
–