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1
LTC1350
3.3V Low Power
EIA/TIA-562 3-Driver/
5-Receiver Transceiver
S
FEATURE
D
U
ESCRIPTIO
s
Low Supply Current
300
µ
A
s
Receivers 4 and 5 Kept Alive
in SHUTDOWN
35
µ
A
s
ESD Protection
±
10kV
s
Operates from a Single 3.3V Supply
s
Uses Small Capacitors
0.1
µ
F
s
Operates to 120k Baud
s
Three-State Outputs are High Impedance
When Off
s
Output Overvoltage Does Not Force Current
Back into Supplies
s
EIA/TIA-562 I/O Lines Can Be Forced to
±
25V
Without Damage
s
Flowthrough Architecture
The LTC1350 is a 3-driver/5-receiver EIA/TIA-562 trans-
ceiver with very low supply current. In the no load condi-
tion, the supply current is only 300
µ
A. The charge pump
only requires four 0.1
µ
F capacitors.
In SHUTDOWN mode, two receivers are kept alive and
the supply current is only 35
µ
A. All RS232 outputs
assume a high impedance state in SHUTDOWN or with
the power off.
The LTC1350 is fully compliant with all data rate and
overvoltage EIA/TIA-562 specifications. The transceiver
can operate up to 120k baud with a 1000pF and 3k
load. Both driver outputs and receiver inputs can be
forced to
±
25V without damage and can survive multiple
±
10kV ESD strikes.
U
S
A
O
PPLICATI
s
Notebook Computers
s
Palmtop Computers
U
A
O
PPLICATI
TYPICAL
3-Drivers/5-Receivers with Shutdown
Quiescent and Shutdown Supply Current vs Temperature
1
2
3
4
5
6
7
8
9
10
11
12
13
14
V
+
V
CC
C1
+
C1
DR1 OUT
RX1 IN
DR2 OUT
RX2 IN
RX3 IN
RX4 IN
DR3 OUT
RX5 IN
ON/OFF
NC
28
27
26
25
24
23
22
21
20
19
18
17
16
15
V
C2
+
C2
DR1 IN
RX1 OUT
DR2 IN
RX2 OUT
RX3 OUT
RX4 OUT
DR3 IN
RX5 OUT
GND
NC
NC
LTC1350
LTC1350 · TA01
TEMPERATURE (°C)
40
QUIESCENT CURRENT (
µ
A)
400
500
600
20
60
LTC1350 · TA02
300
200
20
0
40
80
100
100
0
TEST CONDITION: V
CC
= 3.3V
ALL DRIVER INPUTS TIED TO V
CC
SHUTDOWN CURRENT (
µ
A)
65
75
85
55
45
35
0
QUIESCENT
CURRENT
SHUTDOWN CURRENT
2
LTC1350
A
U
G
W
A
W
U
W
A
R
BSOLUTE
XI
TI
S
W
U
U
PACKAGE/ORDER I FOR ATIO
Supply Voltage (V
CC
) ................................................ 5V
Input Voltage
Driver ....................................... 0.3V to V
CC
+ 0.3V
Receiver ............................................... 25V to 25V
ON/OFF Pin ................................ 0.3V to V
CC
+ 0.3V
Output Voltage
Driver .................................................... 25V to 25V
Receiver .................................... 0.3V to V
CC
+ 0.3V
Short-Circuit Duration
V
+
................................................................... 30 sec
V
................................................................... 30 sec
Driver Output .............................................. Indefinite
Receiver Output .......................................... Indefinite
Operating Temperature Range
Commercial (LTC1350C) ........................ 0
°
C to 70
°
C
Industrial (LTC1350I) ........................ 40
°
C to 85
°
C
Storage Temperature Range ................ 65
°
C to 150
°
C
Lead Temperature (Soldering, 10 sec)................. 300
°
C
ORDER PART
NUMBER
LTC1350CG
LTC1350CN
LTC1350CS
LTC1350IG
LTC1350IN
LTC1350IS
T
JMAX
= 125
°
C,
JA
= 96
°
C/W (G)
T
JMAX
= 125
°
C,
JA
= 56
°
C/W (N)
T
JMAX
= 125
°
C,
JA
= 85
°
C/W (S)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
V
+
V
CC
C1
+
C1
DR1 OUT
RX1 IN
DR2 OUT
RX2 IN
RX3 IN
RX4 IN
DR3 OUT
RX5 IN
ON/OFF
NC
28
27
26
25
24
23
22
21
20
19
18
17
16
15
V
C2
+
C2
DR1 IN
RX1 OUT
DR2 IN
RX2 OUT
RX3 OUT
RX4 OUT
DR3 IN
RX5 OUT
GND
NC
NC
N PACKAGE
28-LEAD PLASTIC DIP
TOP VIEW
S PACKAGE
28-LEAD PLASTIC SOL
G PACKAGE
28-LEAD SSOP
Consult factory for Military grade parts
V
CC
= 3.3V, C1 = C2 = C3 = C4 = 0.1
µ
F, unless otherwise noted.
ELECTRICAL C
C
HARA TERISTICS
C
D
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Any Driver
Output Voltage Swing
3k to GND
Positive
q
3.7
4.5
V
Negative
q
3.7
4.5
V
Logic Input Voltage Level
Input Low Level (V
OUT
= High)
q
1.4
0.8
V
Input High Level (V
OUT
= Low)
q
2.0
1.4
V
Logic Input Current
V
IN
= V
CC
q
5
µ
A
V
IN
= 0V
q
5
µ
A
Output Short-Circuit Current
V
OUT
= 0V
±
10
mA
Output Leakage Current
SHUTDOWN (Note 3), V
OUT
=
±
20V
10
500
µ
A
Any Receiver
Input Voltage Thresholds
Input Low Threshold
q
0.8
1.3
V
Input High Threshold
q
1.7
2.4
V
Hysteresis
q
0.1
0.4
1
V
Input Resistance
V
IN
=
±
10V
3
5
7
k
Output Voltage
Output Low, I
OUT
= 1.6mA (V
CC
= 3.3V)
q
0.2
0.4
V
Output High, I
OUT
= 160
µ
A (V
CC
= 3.3V)
q
3.0
3.2
V
Output Short-Circuit Current
Sinking Current, V
OUT
= V
CC
3
20
mA
Output Leakage Current
SHUTDOWN (Note 3), 0V
V
OUT
V
CC
q
1
10
µ
A
3
LTC1350
V
CC
= 3.3V, C1 = C2 = C3 = C4 = 0.1
µ
F, unless otherwise noted.
ELECTRICAL C
C
HARA TERISTICS
C
D
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Power Supply Generator
V
+
Output Voltage
I
OUT
= 0mA
5.7
V
I
OUT
= 5mA
5.5
V
V
Output Voltage
I
OUT
= 0mA
5.3
V
I
OUT
= 5mA
5.0
V
Supply Rise Time
SHUTDOWN to Turn-On
0.2
ms
Power Supply
V
CC
Supply Current
No Load (All Drivers V
IN
= V
CC
)(Note 2) 0
°
C
T
A
70
°
C
q
0.3
0.6
mA
No Load (All Drivers V
IN
= 0)(Note 2) 0
°
C
T
A
70
°
C
q
0.5
1.0
mA
No Load (All Drivers V
IN
= V
CC
)(Note 2) 40
°
C
T
A
85
°
C
q
0.3
1.0
mA
No Load (All Drivers V
IN
= 0)(Note 2) 40
°
C
T
A
85
°
C
q
0.5
1.5
mA
SHUTDOWN (Note 3)
q
35
50
µ
A
ON/OFF Threshold Low
q
1.4
0.8
V
ON/OFF Threshold High
q
2.0
1.4
V
The
q
denotes specifications which apply over the operating temperature
range of 0
°
C
T
A
70
°
C for commercial grade, 40
°
C
T
A
85
°
C for
Industrial grade.
Note 1: Absolute maximum ratings are those values beyond which the life
of the device may be impaired.
Note 2: Supply current is measured with driver and receiver outputs
unloaded.
Note 3: Supply current measurement in SHUTDOWN mode is performed
with V
ON/OFF
= 0V.
C
C
HARA TERISTICS
AC
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Slew Rate
R
L
= 3k, C
L
= 51pF
8
30
V/
µ
s
R
L
= 3k, C
L
= 1000pF
3
5
V/
µ
s
Driver Propagation Delay
t
HLD
(Figure 1)
q
2
3.5
µ
s
(TTL to EIA/TIA-562)
t
LHD
(Figure 1)
q
2
3.5
µ
s
Receiver Propagation Delay
t
HLR
(Figure 2)
q
0.3
0.8
µ
s
(EIA/TIA-562 to TTL)
t
LHR
(Figure 2)
q
0.3
0.8
µ
s
V
CC
= 5V, C1 = C2 = C3 = C4 = 0.1
µ
F, unless otherwise noted.
4
LTC1350
TYPICAL PERFOR A CE CHARACTERISTICS
W U
Driver Output Voltage
vs Temperature
Receiver Input Thresholds
vs Temperature
Driver Short-Circuit Current
vs Temperature
Driver Leakage in Shutdown
vs Temperature
V
CC
Supply Current
vs Temperature
Supply Current vs Data Rate
TEMPERATURE (°C)
40
5
DRIVER OUTPUT VOLTAGE (V)
4
2
1
0
5
2
0
40
60
LTC1350 · TPC01
3
3
4
1
20
20
80
100
V
CC
= 3.3V
OUTPUT HIGH
V
CC
= 3.3V
OUTPUT LOW
ALL DRIVERS WITH LOAD, R
L
= 3k
TEMPERATURE (°C)
40
THRESHOLD VOLTAGE (V)
1.8
2.0
V
TH
+
V
TH
2.2
20
60
LT1350 · TPC02
1.6
1.4
20
0
40
80
100
1.2
1.0
DATA RATE (k Baud)
0
SUPPLY CURRENT (mA)
20
25
30
60
100
LTC1350 · TPC03
15
10
20
40
80
120
140
5
0
V
CC
= 3.3V
R
L
= 3k
C
L
= 2500pF
3 DRIVERS ACTIVE
TEMPERATURE (°C)
40
0
SUPPLY CURRENT (mA)
0.5
1.5
2.0
2.5
5.0
3.5
0
40
60
LTC1350 · TPC04
1.0
4.0
4.5
3.0
20
20
80
100
R
L
= 3k
3 DRIVERS LOADED
R
L
= 3k
1 DRIVER LOADED
TEMPERATURE (°C)
0
LEAKAGE CURRENT (
µ
A)
60
45
40
35
30
25
20
15
10
5
0
LTC1350 · TPC05
20
70
10
30
40
50
V
OUT
= 20V
V
OUT
= 20V
TEMPERATURE (°C)
40
SHORT-CIRCUIT CURRENT (mA)
14
20
I
SC
I
SC
+
LTC1350 · TPC06
8
4
20
0
40
2
0
16
12
10
6
60
80
100
Receiver Short-Circuit Current
vs Temperature
TEMPERATURE (°C)
40
SHORT-CIRCUIT CURRENT (mA)
35
20
I
SC
I
SC
+
LTC1350 · TPC07
20
10
20
0
40
5
0
40
30
25
15
60
80
100
DRIVER
OUTPUT
R
L
= 3k
C
L
= 1000pF
DRIVER
OUTPUT
R
L
= 3k
INPUT
LTC1350 · TPC08
RECEIVER
OUTPUT
C
L
= 50pF
INPUT
LTC1350 · TPC09
Driver Output Waveforms
Receiver Output Waveform
5
LTC1350
PI FU CTIO S
U
U
U
V
CC
: 3.3V Input Supply Pin. Supply current is typically
35
µ
A in the SHUTDOWN mode. This pin should be de-
coupled with a 0.1
µ
F ceramic capacitor.
GND: Ground Pin.
ON/OFF: TTL/CMOS Compatible Shutdown Pin. A logic
low puts the device in the SHUTDOWN mode with receiv-
ers 4 and 5 kept alive and the supply current equal to 35
µ
A.
All driver and other receiver outputs are in high impedance
state. This pin cannot float.
V
+
: Positive Supply Output. V
+
2V
CC
1V. This pin
requires an external capacitor (C = 0.1
µ
F) for charge
storage. The capacitor may be tied to ground or V
CC
. With
multiple devices, the V
+
and V
pins may be paralleled into
common capacitors. For a large number of devices, in-
creasing the size of the shared common storage capaci-
tors is recommended to reduce ripple.
V
: Negative Supply Output. V
(2V
CC
1.3V). This
pin requires an external capacitor (C = 0.1
µ
F) for charge
storage.
SWITCHI G TI E WAVEFOR S
W
W
U
1.4V
0V
V
CC
0V
V
+
V
0V
DR
INPUT
DR
OUTPUT
1.4V
t
HLD
t
LHD
LTC1350 · F01
0.8V
V
CC
0V
2.4V
RX
INPUT
RX
OUTPUT
1.3V
t
HLR
1.7V
t
LHR
LTC1350 · F02
V
CC
0V
Figure 2. Receiver Propagation Delay Timing
Figure 1. Driver Propagation Delay Timing
C1
+
, C1
, C2
+
, C2
: Commutating Capacitor Inputs. These
pins require two external capacitors (C = 0.1
µ
F): one from
C1
+
to C1
and another from C2
+
to C2
. To maintain
charge pump efficiency, the capacitor's effective series
resistance should be less than 20
.
DR IN: EIA/TIA-562 Driver Input Pins. Inputs are TTL/
CMOS compatible. Inputs should not be allowed to float.
Tie unused inputs to V
CC
.
DR OUT: Driver Outputs at EIA/TIA-562 Voltage Levels.
Outputs are in a high impedance state when in the SHUT-
DOWN mode or V
CC
= 0V. The driver outputs are protected
against ESD to
±
10kV for human body model discharges.
RX IN: Receiver Inputs. These pins can be forced to
±
25V
without damage. The receiver inputs are protected against
ESD to
±
10kV for human body model discharges. Each
receiver provides 0.4V of hysteresis for noise immunity.
RX OUT: Receiver Outputs with TTL/CMOS Voltage Lev-
els. Receiver 1, 2 and 3 outputs are in a high impedance
state when in SHUTDOWN mode to allow data line sharing.
Receivers 4 and 5 are kept alive in SHUTDOWN.
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