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LTC1387CG#PBF

P1-P3P4-P6P7-P9P10-P12
1
LTC1387
Single 5V RS232/RS485
Multiprotocol Transceiver
S
F
EA
T
U
RE
The LTC
®
1387 is a low power reconfigurable CMOS bidi-
rectional transceiver. It can be configured as an RS485
differential port or as two RS232 single-ended ports. An
onboard charge pump uses four 0.1µF capacitors to
generate boosted positive and negative supplies, allowing
the RS232 drivers to meet ±5V output swing require-
ments with only a single 5V supply. A shutdown mode
reduces the I
CC
supply current to 5µA.
The RS232 transceivers are in full compliance with RS232
specification. The RS485 transceiver is in full compliance
with RS485 and RS422 specifications. The RS485 re-
ceiver assumes a known output state when the inputs are
floating or shorted to ground. All interface drivers feature
short-circuit and thermal shutdown protection. An enable
pin allows RS485 driver outputs to be forced into high
impedance which is maintained even when the outputs are
forced beyond supply rails or the power is off. A loop back
mode allows the driver outputs to be connected back to the
receiver inputs for diagnostic self-test.
The LTC1387 is available in 20-pin plastic SSOP and SW
packages.
D
U
ESCRIPTIO
■
Two RS232 Transceivers or One RS485 Transceiver
■
Operates from a Single 5V Supply
■
Guaranteed Receiver Output with Inputs
Floating or Shorted to Ground
■
Logic Selectable Fast/Slow RS485 Driver Slew Rate
■
Low Supply Current: 7mA Typical
■
5µA Supply Current in Shutdown
■
Self-Testing Capability in Loopback Mode
■
Separate Driver and Receiver Enable Controls
■
Driver Maintains High Impedance in Three-State,
Shutdown or with Power Off
■
Receiver Inputs Can Withstand ±25V
■
Point-of-Sale Terminals
■
Software Selectable Multiprotocol Interface Ports
■
Low Power RS485/RS422/RS232/EIA562 Interface
■
Cable Repeaters
■
Level Translators
APPLICATIONS
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
U
A
O
PP
L
IC
AT
ITY
P
I
CA
L
9
DR ENABLE
14
SLEW
8
5V
13
5V
12
5V
18
3
18
3
1920
V
CC1
5V
120Ω
4
LTC1387
LTC1387 • TA01
RECOUT
RS485 INTERFACE
5
6
7
10
17
DR IN
15
11
4
9
LTC1387
RECOUT
15
DR ENABLE
DR IN
5
6
7
8
13
10
17
SLEW
14
5V
12
11
120Ω
4000-FT 24-GAUGE TWISTED PAIR
5V
5V
ALL CAPACITORS: 0.1µF MONOLITHIC CERAMIC TYPE
12
212019
V
CC2
5V
2
LTC1387
A
U
G
W
A
W
U
W
ARB
S
O
LU
T
EXI T
I
S
ORDER PART
NUMBER
(Note 1)
Supply Voltage (V
CC
) ............................................. 6.5V
Input Voltage
Drivers ................................... –0.3V to (V
CC
+ 0.3V)
Receivers ............................................. –25V to 25V
485/232, ON, DXEN
RXEN, SLEW ........................... –0.3V to (V
CC
+ 0.3V)
Output Voltage
Drivers ................................................. –18V to 18V
Receivers ............................... –0.3V to (V
CC
+ 0.3V)
Short-Circuit Duration
Output ........................................................ Indefinite
V
DD
, V
EE
, C1
+
, C1
–
, C2
+
, C2
–
.......................... 30 sec
Operating Temperature Range
LTC1387C .............................................. 0°C to 70°C
LTC1387I ........................................... –40°C to 85°C
Storage Temperature Range ................ –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................ 300°C
WU
U
PACKAGE
/
O
RDER I FOR ATIO
Consult factory for Military grade parts.
T
JMAX
= 125°C, θ
JA
= 120°C/W (G)
T
JMAX
= 125°C, θ
JA
= 75°C/W (SW)
1
2
3
4
5
6
7
8
9
10
TOP VIEW
SW PACKAGE
20-LEAD PLASTIC SO
G PACKAGE
20-LEAD PLASTIC SSOP
20
19
18
17
16
15
14
13
12
11
C1
+
C1
–
V
DD
A
B
Y
Z
485/232
DXEN
GND
C2
+
C2
–
V
CC
R
A
R
B
D
Y
D
Z
/SLEW
ON
RXEN
V
EE
DC ELECTRICAL CHARACTERISTICS
LTC1387CG
LTC1387CSW
LTC1387IG
LTC1387ISW
T
A
= 25°C, V
CC
= 5V, C1 = C2 = C3 = C4 = 0.1µF (Notes 2, 3), unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
RS485 Driver (485/232 = High, ON = DXEN = High)
V
OD1
Differential Driver Output Voltage (Unloaded) I
O
= 0 ● 6V
V
OD2
Differential Driver Output Voltage (With Load) Figure 1, R = 50Ω (RS422) ● 2.0 6 V
Figure 1, R = 27Ω (RS485)
● 1.5 6 V
∆V
OD
Change in Magnitude of Driver Differential Figure 1, R = 27Ω or R = 50Ω ● 0.2 V
Output Voltage for Complementary Output States
V
OC
Driver Common Mode Output Voltage Figure 1, R = 27Ω or R = 50Ω ● 3V
∆V
OC
Change in Magnitude of Driver Common Mode Figure 1, R = 27Ω or R = 50Ω ● 0.2 V
Output Voltage for Complementary Output States
I
OSD
Driver Short-Circuit Current V
O
= –7V, 12V; V
O
= High ● 35 250 mA
V
O
= –7V, 12V; V
O
= Low (Note 4) ● 10 250 mA
I
OZD
Three-State Output Current (Y, Z) –7V ≤ V
O
≤ 12V ±5 500 µA
RS232 Driver (485/232 = Low, ON = DXEN = High)
V
O
Output Voltage Swing Figure 4, R
L
= 3k, Positive ● 5 6.5 V
Figure 4, R
L
= 3k, Negative ● –5 –6.5 V
I
OSD
Output Short-Circuit Current V
O
= 0V ● ±17 ±60 mA
Driver Inputs and Control Inputs
V
IH
Input High Voltage D
Y
, D
Z
, DXEN, RXEN, ON, 485/232, SLEW ● 2V
V
IL
Input Low Voltage D
Y
, D
Z
, DXEN, RXEN, ON, 485/232, SLEW ● 0.8 V
I
IN
Input Current D
Y
, D
Z
, DXEN, RXEN, ON, 485/232 ● ±0.1 ±10 µA
SLEW (Note 5)
● 5 15 µA
3
LTC1387
DC ELECTRICAL CHARACTERISTICS
T
A
= 25°C, V
CC
= 5V, C1 = C2 = C3 = C4 = 0.1µF (Notes 2, 3), unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
RS485 Receiver (485/232 = High, ON = RXEN = High)
V
TH
Differential Input Threshold Voltage –7V ≤ V
CM
≤ 12V ● –0.20 0.20 V
∆V
TH
Input Hysteresis V
CM
= 0V 40 mV
I
IN
Input Current (A, B) V
IN
= 12V ● 1mA
V
IN
= –7V ● –0.8 mA
R
IN
Input Resistance –7V ≤ V
IN
≤ 12V ● 12 24 kΩ
RS232 Receiver (485/232 = Low, ON = RXEN = High)
V
TH
Receiver Input Voltage Threshold Input Low Threshold ● 0.8 V
Input High Threshold
● 2.4 V
∆V
TH
Receiver Input Hysteresis 0.6 V
R
IN
Receiver Input Resistance V
IN
= ±10V 3 5 7 kΩ
Receiver Output (ON = RXEN = High)
V
OH
Receiver Output High Voltage I
O
= –3mA, V
IN
= 0V, 485/232 = Low ● 3.5 4.6 V
V
OL
Receiver Output Low Voltage I
O
= 3mA, V
IN
= 3V, 485/232 = Low ● 0.2 0.4 V
I
OSR
Short-Circuit Current 0V ≤ V
O
≤ V
CC
● 785mA
I
OZR
Three-State Output Current RXEN = 0V ● ±0.1 ±10 µA
Power Supply Generator
V
DD
V
DD
Output Voltage No Load, ON = DXEN = RXEN = High 8 V
I
DD
= –5mA, ON = DXEN = RXEN = High 7 V
V
EE
V
EE
Output Voltage No Load, ON = DXEN = RXEN = High –7.7 V
I
EE
= 5mA, ON = DXEN = RXEN = High –7.0 V
Power Supply
I
CC
V
CC
Supply Current No Load, ON = DXEN = RXEN = High ● 725 mA
Shutdown, ON = DXEN = RXEN = 0V
● 5 100 µA
AC ELECTRICAL CHARACTERISTICS
T
A
= 25°C, V
CC
= 5V, C1 = C2 = C3 = C4 = 0.1µF (Notes 2, 3), unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
RS232 Mode (ON = DXEN = RXEN = High, 485/232 = Low)
SR Slew Rate Figure 4, R
L
= 3k, C
L
= 15pF ● 30 V/µs
Figure 4, R
L
= 3k, C
L
= 1000pF ● 4V/µs
t
T
Transition Time Figure 4, R
L
= 3k, C
L
= 2500pF ● 0.22 1.9 3.1 µs
t
PLH
Driver Input to Output Figures 4, 10, R
L
= 3k, C
L
= 15pF ● 0.6 4 µs
t
PHL
Driver Input to Output Figures 4, 10, R
L
= 3k, C
L
= 15pF ● 0.6 4 µs
t
PLH
Receiver Input to Output Figures 5, 11 ● 0.3 6 µs
t
PHL
Receiver Input to Output Figures 5, 11 ● 0.4 6 µs
RS485 Mode (Fast Slew Rate, ON = DXEN = High, 485/232 = High, SLEW = High)
t
PLH
Driver Input to Output Figures 2, 7, R
L
= 54Ω, C
L
= 100pF ● 15 40 70 ns
t
PHL
Driver Input to Output Figures 2, 7, R
L
= 54Ω, C
L
= 100pF ● 15 40 70 ns
t
SKEW
Driver Output to Output Figures 2, 7, R
L
= 54Ω, C
L
= 100pF ● 515 ns
t
r
, t
f
Driver Rise or Fall Time Figures 2, 7, R
L
= 54Ω, C
L
= 100pF ● 31540 ns
P1-P3P4-P6P7-P9P10-P12

LTC1387CG#PBF

Mfr. #:
Buy LTC1387CG#PBF
Manufacturer:
Analog Devices Inc.
Description:
RS-232 Interface IC +5V RS232/RS485 Transceiver
Lifecycle:
New from this manufacturer.
Delivery:
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