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
s
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
LTC1391
ABSOLUTE
(Note 1)
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
S0 1
S1 2
S2 3
S3 4
S4 5
S5 6
S6 7
S7 8
16
V
+
15 D
14 V
–
13 D
OUT
12 D
IN
11 CS
10 CLK
9
GND
Total Supply Voltage (V
+
to V
–
) .............................. 15V
Input Voltage
Analog Inputs/Outputs ..... (V
–
– 0.3V) to (V
+
+ 0.3V)
Digital Inputs .........................................– 0.3V to 15V
Digital Outputs ..........................– 0.3V to (V
+
+ 0.3V)
Power Dissipation .............................................. 500mW
Operating Temperature Range
LTC1391C ............................................... 0°C to 70°C
LTC1391I ........................................... – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
LTC1391CGN
LTC1391CN
LTC1391CS
LTC1391IGN
LTC1391IN
LTC1391IS
GN PART MARKING
1391
1391I
GN PACKAGE
N PACKAGE
16-LEAD PLASTIC SSOP 16-LEAD PDIP
S PACKAGE
16-LEAD PLASTIC SO
T
JMAX
= 125°C,
θ
JA
= 110°C/ W (GN)
T
JMAX
= 125°C,
θ
JA
= 70°C/ W (N)
T
JMAX
= 125°C,
θ
JA
= 100°C/ W (S)
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
Switch
V
ANALOG
Analog Signal Range
R
ON
On-Resistance
(Note 2)
V
S
=
±3.5V,
I
D
= 1mA
CONDITIONS
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
+
= 5V, V
–
= – 5V, GND = 0V, unless otherwise specified.
MIN
q
TYP
MAX
5
75
UNITS
V
Ω
Ω
Ω
%
%/°C
–5
T
MIN
= 0°C (LTC1391C)
T
MIN
= –40°C (LTC1391I)
25°C
T
MAX
= 70°C (LTC1391C)
T
MAX
= 85°C (LTC1391I)
45
75
120
∆R
ON
vs V
S
∆R
ON
vs Temperature
I
S(OFF)
I
D(OFF)
I
D(ON)
Digital
V
INH
V
INL
V
OH
V
OL
High Level Input Voltage
Low Level Input Voltage
High Level Output Voltage
Low Level Output Voltage
V
+
= 5.25V
V
+
= 4.75V
V
IN
= 5V, 0V
V
+
= 4.75V, I
O
= – 10µA
V
+
= 4.75V, I
O
= – 360µA
V
+
= 4.75V, I
O
= 1.6mA
q
q
q
q
q
20
0.5
V
S
= 4V, V
D
= – 4V, V
S
= – 4V, V
D
= 4V
Channel Off
V
S
= 4V, V
D
= – 4V, V
S
= – 4V, V
D
= 4V
Channel Off
V
S
= V
D
=
±4V
Channel On
±0.05
q
Off Input Leakage
Off Output Leakage
On Channel Leakage
±5
±20
±5
±20
±5
±20
±0.05
q
±0.05
q
2.4
0.8
±5
2.4
4.74
4.50
0.5
0.8
I
INL
, I
INH
Input Current
sn1391 1391fas
2
U
nA
nA
nA
nA
nA
nA
V
V
µA
V
V
V
W
U
U
W W
W
LTC1391
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
Dynamic
f
CLK
t
ON
t
OFF
t
OPEN
OIRR
Q
INJ
C
S(OFF)
C
D(0FF)
Supply
I
+
I
–
Positive Supply Current
Negative Supply Current
All Logic Inputs Tied Together, V
IN
= 0V or 5V
All Logic Inputs Tied Together, V
IN
= 0V or 5V
q
q
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
+
= 5V, V
–
= – 5V, GND = 0V, unless otherwise specified.
CONDITIONS
(Note 2)
V
S
= 2.5V, R
L
= 1k, C
L
= 35pF
V
S
= 2.5V, R
L
= 1k, C
L
= 35pF
35
V
S
= 2V
P–P
, R
L
= 1k, f = 100kHz
R
S
= 0, C
L
= 1000pF, V
S
= 1V (Note 2)
260
100
155
70
±2
5
10
15
– 15
40
– 40
±10
MIN
TYP
MAX
5
400
200
UNITS
MHz
ns
ns
ns
dB
pC
pF
pF
µA
µA
Clock Frequency
Enable Turn-On Time
Enable Turn-Off Time
Break-Before-Make Interval
Off Isolation
Charge Injection
Input Off Capacitance
Output Off Capacitance
The
q
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C.
V
+
= 2.7V, V
–
= GND = 0V, unless otherwise specified.
SYMBOL PARAMETER
Switch
V
ANALOG
Analog Signal Range
R
ON
On-Resistance
(Note 2)
V
S
= 1.2V, I
O
= 1mA
T
MIN
= 0°C (LTC1391C)
T
MIN
= –40°C (LTC1391I)
25°C
T
MAX
= 70°C (LTC1391C)
T
MAX
= 85°C (LTC1391I)
∆R
ON
vs V
S
∆R
ON
vs Temperature
I
S(OFF)
I
D(OFF)
I
D(ON)
Digital
V
INH
V
INL
V
OH
V
OL
High Level Input Voltage
Low Level Input Voltage
High Level Output Voltage
Low Level Output Voltage
V
+
= 3.0V
V
+
= 2.4V
V
IN
= 2.7V, 0V
V
+
= 2.7V, I
O
= – 20µA
V
+
= 2.7V, I
O
= – 400µA
V
+
= 2.7V, I
O
= 20µA
V
+
= 2.7V, I
O
= 400µA
q
q
q
q
q
q
CONDITIONS
MIN
0
TYP
MAX
2.7
300
UNITS
V
Ω
Ω
Ω
%
%/°C
250
300
350
20
0.5
V
S
= 2.5V, V
D
= 0.5V; V
S
= 0.5V, V
D
= 2.5V (Note 3)
Channel Off
V
S
= 2.5V, V
D
= 0.5V; V
S
= 0.5V, V
D
= 2.5V (Note 3)
Channel Off
V
S
= V
D
= 0.5V, 2.5V (Note 3)
Channel On
±0.05
q
Off Input Leakage
Off Output Leakage
On Channel Leakage
±5
±20
±5
±20
±5
±20
nA
nA
nA
nA
nA
nA
V
±0.05
q
±0.05
q
2.0
0.8
±5
2.0
2.68
2.30
0.01
0.20
0.8
V
µA
V
V
V
V
I
INL
, I
INH
Input Current
sn1391 1391fas
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LTC1391
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
Dynamic
f
CLK
t
ON
t
OFF
t
OPEN
QIRR
Q
INJ
C
S(OFF)
C
D(OFF)
Supply
I
+
Positive Supply Current
All Logic Inputs Tied Together, V
IN
= 0V or 2.7V
q
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
+
= 2.7V, V
–
= GND = 0V, unless otherwise specified.
CONDITIONS
(Note 2)
V
S
= 1.5V, R
L
= 1k, C
L
= 35pF (Note 4)
V
S
= 1.5V, R
L
= 1k, C
L
= 35pF (Note 4)
(Note 4)
V
S
= 2V
P–P
, R
L
= 1k, f = 100kHz
R
S
= 0, C
L
= 1000pF, V
S
= 1V (Note 2)
125
490
190
290
70
±1
5
10
0.2
2
±5
MIN
TYP
MAX
5
800
400
UNITS
MHz
ns
ns
ns
dB
pC
pF
pF
µA
Clock Frequency
Enable Turn-On Time
Enable Turn-Off Time
Break-Before-Make Interval
Off Isolation
Charge Injection
Input Off Capacitance
Output Off Capacitance
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
Guaranteed by Design.
Note 3:
Leakage current with a single 2.7V supply is guaranteed by
correlation with the
±5V
leakage current specifications.
Note 4:
Timing specifications with a single 2.7V supply are guaranteed by
correlation with the
±5V
timing specifications.
TYPICAL PERFOR A CE CHARACTERISTICS
On-Resistance vs Temperature
300
250
V
+
= 2.7V
V
–
= 0V
V
S
= 1.2V
1.2
1.1
1.0
OUTPUT VOLTAGE (V)
200
150
100
50
0
–40
V
+
= 5V
V
–
= –5V
V
S
= 0V
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
V
+
= 5V
V
–
= –5V
OUTPUT VOLTAGE (V)
ON-RESISTANCE (Ω)
–20
20
40
60
0
TEMPERATURE (°C)
4
U W
80
1391 G01
Driver Output Low Voltage
vs Output Current
0.65
Driver Output Low Voltage
vs Temperature
0.60
V
+
= 5V
V
–
= –5V
I
O
= 1.8mA
T
A
= 25°C
V
+
= 2.7V
V
–
= 0V
0.55
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
–40
0.9
V
+
= 2.7V
V
–
= 0V
I
O
= 400µA
0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
OUTPUT CURRENT (mA)
1391 G02
–20
40
60
0
20
TEMPERATURE (°C)
80
1391 G03
sn1391 1391fas
LTC1391
TYPICAL PERFOR A CE CHARACTERISTICS
Driver Output High Voltage
vs Output Current
0
–0.5
OUTPUT CURRENT (mA)
–1.0
–1.5
–2.0
–2.5
–3.0
–3.5
–4.0
2.0
2.5
3.0
3.5
4.0
OUTPUT VOLTAGE (V)
T
A
=25°C
4.5
5.0
1391 G04
V
+
= 2.7V
V
–
= 0V
OUTPUT VOLTAGE (V)
PIN FUNCTIONS
S0, S1, S2, S3, S4, S5, S6, S7 (Pins 1, 2, 3, 4, 5, 6, 7,
8):
Analog Multiplexer Inputs.
GND (Pin 9):
Digital Ground. Connect to system ground.
CLK (Pin 10):
System Clock (TTL/CMOS Compatible). The
clock synchronizes the channel selection bits and the
serial data transfer from D
IN
to D
OUT
.
CS (Pin 11):
Channel Select Input (TTL/CMOS Compat-
ible). A logic high on this input enables the LTC1391 to
read in the channel selection bits and allows digital data
transfer from D
IN
to D
OUT
. A logic low on this input puts
D
OUT
into three-state and enables the selected channel for
analog signal transmission.
D
IN
(Pin 12):
Digital Input (TTL/CMOS Compatible). Input
for the channel selection bits.
D
OUT
(Pin 13):
Digital Output (TTL/CMOS Compatible).
Output from the internal shift register.
V
–
(Pin 14):
Negative Supply. For
±5V
dual supply appli-
cations, |V
–
| should not exceed |V
+
|by more than 20% for
proper channel selection.
D (Pin 15):
Analog Multiplexer Output.
V
+
(Pin 16):
Positive Supply.
U W
Driver Output High Voltage
vs Temperature
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
–40
–20
40
60
0
20
TEMPERATURE (°C)
80
1391 G05
V
+
= 5V
V
–
= –5V
I
O
= 1.6mA
V
+
= 5V
V
–
= –5V
V
+
= 2.7V
V
–
= 0V
I
O
= 400µA
U
U
U
sn1391 1391fas
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