LTC1391
8-Channel
Analog Multiplexer with
Cascadable Serial Interface
FEATURES
s
s
s
s
s
s
s
s
s
s
DESCRIPTIO
Low R
ON
: 45Ω
Single 2.7V to
±5V
Supply Operation
Low Charge Injection
Serial Digital Interface
Analog Inputs May Extend to Supply Rails
Low Leakage:
±5nA
Max
Guaranteed Break-Before-Make
TTL/CMOS Compatible for All Digital Inputs
Cascadable to Allow Additional Channels
Can Be Used as a Demultiplexer
The LTC
®
1391 is a high performance CMOS 8-to-1 analog
multiplexer. It features a serial digital interface that allows
several LTC1391s to be daisy-chained together, increas-
ing the number of MUX channels available using a single
digital port.
The LTC1391 features a typical R
ON
of 45Ω, a typical
switch leakage of 50pA and guaranteed break-before-
make operation. Charge injection is
±10pC
maximum. All
digital inputs are TTL and CMOS compatible when oper-
ated from single or dual supplies. The inputs can with-
stand 100mA fault current.
The LTC1391 is available in 16-pin PDIP, SSOP and
narrow SO packages. For applications requiring 2-way
serial data transmission, see the LTC1390 data sheet.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
s
s
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Data Acquisition Systems
Communication Systems
Signal Multiplexing/Demultiplexing
TYPICAL APPLICATIO
3V, 8-Channel 12-Bit ADC
0.1µF
OPTIONAL A/D
INPUT FILTER
3V
1
2
3
ANALOG
INPUTS
4
5
6
7
8
S0
S1
S2
S3
S4
S5
S6
S7
LTC1391
V
+
D
V
–
D
OUT
D
IN
CS
CLK
GND
DATA IN
CLK
CS
DATA OUT
16
15
14
13
12
11
10
9
1
2
3
4
V
REF
+IN
–IN
GND
V
CC
LTC1285
D
OUT
CLK
8
7
6
5
1µF
ON-RESISTANCE (Ω)
CS/SHDN
SERIAL INTERFACE
TO MUX AND ADC
1391 TA01
U
On-Resistance vs
Analog Input Voltage
300
T
A
= 25°C
250
200
150
100
50
V
+
= 5V
V
–
= –5V
V
+
= 2.7V
V
–
= 0V
0
–5 –4 –3 –2 –1 0 1 2 3
ANALOG INPUT VOLTAGE (V)
4
5
1391 TA02
U
U
sn1391 1391fas
1
LINER [ LINEAR TECHNOLOGY ]
