1
LTC1346A
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10Mbps DCE/DTE
V.35 Transceiver
■
Single Chip Provides Complete Differential Signal
Interface for V.35 Port
■
Drivers and Receivers Will Withstand Repeated
±10kV ESD Pulses
■
Operates from ±5V Supplies
■
10Mbaud Transmission Rate
■
Meets CCITT V.35 Specification
■
Shutdown Mode Reduces I
CC
to Below 1µA
■
Selectable Transmitter and Receiver Configurations
■
Independent Driver/Receiver Enables
■
Transmitter Maintains High Impedance When
Disabled, Shut Down or with Power Off
■
Transmitters Are Short-Circuit Protected
The LTC
®
1346A is a single chip transceiver that provides
the differential clock and data signals for a V.35 interface
from ±5V supplies. Combined with an external resistor
termination network and an LT
®
1134A RS232 transceiver
for the control signals, the LTC1346A forms a complete low
power DTE or DCE V.35 interface port.
The LTC1346A features three current output differential
transmitters and three differential receivers. The transceiver
can be configured for DTE or DCE operation or shutdown
using three Select pins. In the Shutdown mode, the supply
current is reduced to below 1µA.
The LTC1346A transceiver operates up to 10Mbaud. All
transmitters feature short-circuit protection. Both the
transmitter outputs and the receiver outputs can be forced
into a high impedance state. The transmitter outputs and
receiver inputs feature ±10kV ESD protection.
■
Modems
■
Telecommunications
■
Data Routers
VCC1
5V
2
1
4
1
2
24
23
12
DTE DCE
10
11
16
15
0.1
m
FLTC1346A LTC1346ABI
627T500/1250
BI
627T500/1250
BI TECHNOLOGIES
627T500/1250 (SOIC)
VCC2
5V
0.1
m
F
2
T
TXD (103)
SCTE (113)
TXC (114)
RXC (115)
RXD (104)
GND (102)
T
5
3
4
22
21
10
11
9
14
13
DX RX
T T
9
14
13
18
17
1
4
2
24
23
T T
10
12
11
16
15
12
78
3
5
4
22
21
T T
78
11
8
7
10
9
14
13
3
5
6
8
7VCC2
VCC1
6
20
19
3
T T
RX
RX
RX
12
LTC1346 • TA01
DX
DX
DX
50
W
=125
W
T
50
W
+
VEE2
–5V
0.1
m
F
1
+
+
VEE1
–5V
0.1
m
F+
DX RX
Clock and Data Signals for V.35 Interface
FEATURES
DESCRIPTIO
U
APPLICATIO S
U
TYPICAL APPLICATIO
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
2
LTC1346A
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A
U
G
W
A
W
U
W
ARBSOLUTEXI T
IS
WU
U
PACKAGE/ORDER I FOR ATIO
T
JMAX
= 150°C,
θ
JA
= 85°C/W
(Note 1)
Supply Voltage
V
CC
.................................................................... 6.5V
V
EE
................................................................... –6.5V
Input Voltage
Transmitters ........................... –0.3V to (V
CC
+ 0.3V)
Receivers............................................... – 18V to 18V
S0, S1, S2 ............................... –0.3V to (V
CC
+ 0.3V)
Output Voltage
Transmitters .......................................... –18V to 18V
Receivers................................ –0.3V to (V
CC
+ 0.3V)
Short-Circuit Duration
Transmitter Output ..................................... Indefinite
Receiver Output .......................................... Indefinite
Operating Temperature Range
LTC1346AC ............................................ 0°C to 70°C
Storage Temperature Range ................ –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
V
EE
V
CC
GND
T1
T2
T3
S1
S2
R3
R2
R1
S0
Y1
Z1
Y2
Z2
Y3
Z3
A3
B3
A2
B2
A1
B1
SW PACKAGE
24-LEAD PLASTIC SO WIDE
TOP VIEW
ORDER PART
NUMBER
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OD
Transmitter Differential Output Voltage –4V ≤ V
OS
≤ 4V (Figure 1) ●0.44 0.55 0.66 V
V
OC
Transmitter Common Mode Output Voltage V
OS
= 0V (Figure 1) ●–0.6 0 0.6 V
I
OH
Transmitter Output High Current V
Y, Z
= 0V ●–12.6 – 11 – 9.4 mA
I
OL
Transmitter Output Low Current V
Y, Z
= 0V ●9.4 11 12.6 mA
I
OZ
Transmitter Output Leakage Current –5V ≤ V
Y, Z
≤ 5V, S1 = S2 = 0V ±1±20 µA
●±100 µA
R
O
Transmitter Output Impedance – 2V ≤ V
Y, Z
≤ 2V 100 kΩ
V
TH
Differential Receiver Input Threshold Voltage – 7V ≤ (V
A
+ V
B
)/2 ≤ 12V ●25 200 mV
∆V
TH
Receiver Input Hysterisis – 7V ≤ (V
A
+ V
B
)/2 ≤ 12V 50 mV
I
IN
Receiver Input Current (A, B) – 7V ≤ V
A, B
≤ 12V ●0.7 mA
R
IN
Receiver Input Impedance – 7V ≤ V
A, B
≤ 12V ●17.5 30 kΩ
V
OH
Receiver Output High Voltage I
O
= 4mA, V
A, B
= 0.2V ●34.5 V
V
OL
Receiver Output Low Voltage I
O
= 4mA, V
A, B
= –0.2V ●0.2 0.4 V
I
OSR
Receiver Output Short-Circuit Current 0V ≤ V
O
≤ V
CC
●74085 mA
I
OZR
Receiver Three-State Output Current S0 = V
CC
, 0V ≤ V
O
≤ V
CC
●±10 µA
V
IH
Logic Input High Voltage T, S0, S1, S2 ●2V
V
IL
Logic Input Low Voltage T, S0, S1, S2 ●0.8 V
I
IN
Logic Input Current T, S0, S1, S2 ●±10 µA
DC ELECTRICAL CHARACTERISTICS
LTC1346ACSW
The ● denotes specifications which apply over the full operating
temperature range. VCC = 5V ±5%, VEE = – 5V ±5% (Note 2)
Consult LTC Marketing for parts specified with wider operating temperature
ranges.
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LTC1346A
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SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
CC
V
CC
Supply Current V
OS
= 0V, S0 = Low, S1 = S2 = High (Figure 1) ●40 50 mA
No Load, S0 = Low, S1 = S2 = High ● 6 9 mA
Shutdown, S0 = V
CC
,
S1 = S2 = 0V ●0.1 100 µA
I
EE
V
EE
Supply Current V
OS
= 0V, S0 = Low, S1 = S2 = High (Figure 1) ●–40 –50 mA
No Load, S0 = Low, S1 = S2 = High ● –6 –9 mA
Shutdown, S0 = V
CC
,
S1 = S2 = 0V ●–0.1 –100 µA
t
r
, t
f
Transmitter Rise or Fall Time V
OS
= 0V (Figures 1, 3) ●740 ns
t
PLH
Transmitter Input to Output V
OS
= 0V (Figures 1, 3) ●25 70 ns
t
PHL
Transmitter Input to Output V
OS
= 0V (Figures 1, 3) ●30 70 ns
t
SKEW
Transmitter Output to Output V
OS
= 0V (Figures 1, 3) 5 ns
t
PLH
Receiver Input to Output V
OS
= 0V (Figures 1, 4) ●50 100 ns
t
PHL
Receiver Input to Output V
OS
= 0V (Figures 1, 4) ●55 100 ns
t
SKEW
Differential Receiver Skew, t
PLH
– t
PHL
V
OS
= 0V (Figures 1, 4) 5 ns
t
ZL
Receiver Enable to Output Low (Active Mode) C
L
= 15pF, SW1 Closed (Figures 2, 5) ●40 70 ns
Receiver Enable to Output Low C
L
= 15pF, SW1 Closed (Figures 2, 5) 2 µs
(from Shutdown, Note 3)
t
ZH
Receiver Enable to Output High (Active Mode) C
L
= 15pF, SW2 Closed (Figures 2, 5) ●35 70 ns
Receiver Enable to Output High C
L
= 15pF, SW2 Closed (Figures 2, 5) 2 µs
(from Shutdown, Note 3)
t
LZ
Receiver Disable from Low C
L
= 15pF, SW1 Closed (Figures 2, 5) ●30 70 ns
t
HZ
Receiver Disable from High C
L
= 15pF, SW2 Closed (Figures 2, 5) ●35 70 ns
AC ELECTRICAL CHARACTERISTICS
Note 1: The Absolute Maximum Ratings are those values beyond which
the life of a device may be impaired.
Note 2: All currents into device pins are positive; all currents out of device
pins are termed negative. All voltages are referenced to device ground
unless otherwise specified.
Note 3: Receiver enable to output valid high or low from Shutdown is
typically 2µs.
TYPICAL PERFOR A CE CHARACTERISTICS
UW
TEMPERATURE (˚C)
–50
OUTPUT CURRENT (mA)
25
1346A G01
11
10
–25 0 50
9
13
12
75 100 125
V
CC
= 5V
V
EE
= –5V
Transmitter Output Current
vs Temperature
OUTPUT VOLTAGE (V)
–2.0
OUTPUT CURRENT (mA)
11
12
2.0
1346A G02
10
9 –1.0 01.0
13
–1.5 –0.5 0.5 1.5
T
A
= 25°C
V
CC
= 5V
V
EE
= –5V
Transmitter Output Current
vs Output Voltage
Transmitter Output Skew
vs Temperature
TEMPERATURE (˚C)
–50
TIME (ns)
25
1346A G03
10
5
–25 0 50
0
20
15
75 100 125
V
CC
= 5V
V
EE
= –5V
The ● denotes specifications which apply over the full operating
temperature range. VCC = 5V ±5%, VEE = – 5V ±5% (Note 2)
4
LTC1346A
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TYPICAL PERFOR A CE CHARACTERISTICS
UW
B1 (Pin 13): Receiver 1 Inverting Input
A1 (Pin 14): Receiver 1 Noninverting Input
B2 (Pin 15): Receiver 2 Inverting Input
A2 (Pin 16): Receiver 2 Noninverting Input
B3 (Pin 17): Receiver 3 Inverting Input
A3 (Pin 18): Receiver 3 Noninverting Input
Z3 (Pin 19): Transmitter 3 Inverting Output
Y3 (Pin 20): Transmitter 3 Noninverting Output
Z2 (Pin 21): Transmitter 2 Inverting Output
Y2 (Pin 22): Transmitter 2 Noninverting Output
Z1 (Pin 23): Transmitter 1 Inverting Output
Y1 (Pin 24): Transmitter 1 Noninverting Output
V
EE
(Pin 1):
Negative Supply, –4.75V ≥ V
EE
≥ –5.25V
V
CC
(Pin 2): Positive Supply, 4.75V ≤ V
CC
≤ 5.25V
GND (Pin 3): Ground
T1 (Pin 4): Transmitter 1 Input, TTL Compatible
T2 (Pin 5): Transmitter 2 Input, TTL Compatible
T3 (Pin 6): Transmitter 3 Input, TTL Compatible
S1 (Pin 7): Select Input 1, TTL Compatible
S2 (Pin 8): Select Input 2, TTL Compatible
R3 (Pin 9): Receiver 3 Output, TTL Compatible
R2 (Pin 10): Receiver 2 Output, TTL Compatible
R1 (Pin 11): Receiver 1 Output, TTL Compatible
S0 (Pin 12): Select Input 0, TTL Compatible
PIN FUNCTIONS
UUU
INPUT
0.2V/DIV
INPUT
5V/DIV
OUTPUT
0.2V/DIV
1346A G07 1346A G08 1346A G09
INPUT A–B
1V/DIV
Receiver Enable from Shutdown
INPUT S0
5V/DIV
OUTPUT
5V/DIV
OUTPUT
5V/DIV
Receiver Output WaveformsTransmitter Output Waveforms
TEMPERATURE (˚C)
–50
CURRENT (mA)
CURRENT (mA)
25
1346A G06
–35
–40
–25 0 50
–45
–25
–30
–6.0
–6.5
–7.0
–5.0
–5.5
75 100 125
LOADED
NO LOAD
V
CC
= 5V
V
EE
= –5V
IEE Supply Current vs Temperature
TEMPERATURE (˚C)
–50
CURRENT (mA)
CURRENT (mA)
25
1346A G05
35
30
–25 0 50
25
45
40
6.5
6.0
5.5
7.5
7.0
75 100 125
LOADED
NO LOAD
VCC = 5V
VEE = –5V
TEMPERATURE (˚C)
–50
TIME (ns)
25
1346A G04
10
5
–25 0 50
0
20
15
75 100 125
V
CC
= 5V
V
EE
= –5V
Receiver tPLH – tPHL
vs Temperature ICC Supply Current vs Temperature
5
LTC1346A
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FU CTIO TABLES
UU
Transmitter and Receiver Configuration
S0 S1 S2 DX ON RX ON Description
000 —1, 2, 3 All RX ON, All DX OFF
100— —All OFF, Shutdown
0101, 2, 3 1, 2 DCE Mode
1101, 2, 3 — DCE Mode, All RX OFF
0011, 2 1, 2, 3 DTE Mode
1011, 2 — DTE Mode, All RX OFF
0111, 2, 3 1, 2, 3 All ON
1111, 2, 3 — All DX ON, All RX OFF
Transmitter
INPUTS OUTPUTS
CONFIGURATION S0 S1 S2 T Y1 AND Y2 Z1 AND Z2 Y3 Z3
All OFF 0 0 0 X Z Z Z Z
Shutdown 1 0 0 X Z Z Z Z
DCE or All ON X 1 X 0 0 1 0 1
DCE or All ON X 1 X 1 1 0 1 0
DTE X 0 1 0 01ZZ
DTE X 0 1 1 10ZZ
Receiver
INPUTS OUTPUTS
CONFIGURATION S0 S1 S2 A – B R1 AND R2 R3
All Rx ON 0 0 0 ≤ –0.2V 0 0
All Rx ON 0 0 0 ≥0.2V 1 1
Shutdown 1 0 0 X Z Z
DCE 0 1 0 ≤ –0.2V 0 Z
DCE 0 1 0 ≥0.2V 1 Z
Disabled 1 1 0 X Z Z
DTE or All ON 0 X 1 ≤ –0.2V 0 0
DTE or All ON 0 X 1 ≥0.2V 1 1
Disabled 1 X 1 X Z Z
TEST CIRCUITS
C
L
1k
LTC1346A • F02
SW1
SW2
V
CC
RECEIVER
OUTPUT
Figure 2. Receiver Output Enable and Disable Timing Test Load
15pFS0
R
50Ω
125Ω
Y
Z
Z
Y
T125Ω
50Ω
50Ω
LTC1346A • F01
50Ω
A
B
V
OD
V
OS
V
OC
= (V
Y
+ V
Z
)/2
Figure 1. V.35 Transmitter/Receiver Test Circuit
6
LTC1346A
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SWITCHI G TI E WAVEFOR S
UW
W
Figure 5. Receiver Enable and Disable Times
1.5V
3V
0V
S0 f = 1MHz: t
r
≤ 10ns: t
f
≤ 10ns 1.5V
R
V
OL
5V
t
ZL
t
LZ
0.5V
OUTPUT NORMALLY LOW
0V
LTC1346A • F05
1.5V
1.5V
t
ZH
V
OH
OUTPUT NORMALLY HIGH t
HZ
0.5V
R
1.5V
3V
0V
T
Y – Z
f = 1MHz: tr ≤ 10ns: tf ≤ 10ns 1.5V
–VO
VO
tSKEW
1/2 VO
LTC1346A • F03
tPLH
tr
90%
50%
10%
tPHL
tf
90%
50%
10%
VO
tSKEW
VDIFF = V(Y) – V(Z)
Z
Y
Figure 4. V.35 Receiver Propagation Delays
VOD/2
A – B
R
VOL
VOH
LTC1346A • F04
tPLH tPHL
–VOD/2
1.5V
1.5V
0V 0V
INPUT
OUTPUT
f = 1MHz: tr ≤ 10ns: tf ≤ 10ns
Figure 3. V.35 Transmitter Propagation Delays
7
LTC1346A
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APPLICATIONS INFORMATION
WUUU
Review of CCITT Recommendation V.35
Electrical Specifications
V.35 is a CCITT recommendation for synchronous data
transmission via modems. Appendix 2 of the recommen-
dation describes the electrical specifications which are
summarized below:
1. The interface cable is a balanced twisted pair with 80Ω
to 120Ω impedance.
2. The transmitter’s source impedance is between 50Ω
and 150Ω.
3. The transmitter’s resistance between shorted termi-
nals and ground is 150Ω ±15Ω.
4. When terminated by a 100Ω resistive load, the termi-
nal-to-terminal voltage should be 0.55V ±20%.
5. The transmitter’s rise time should be less than 1% of
the signal pulse or 40ns, whichever is greater.
6. The common mode voltage at the transmitter output
should not exceed 0.6V.
7. The receiver impedance is 100Ω ±10Ω.
8. The receiver impedance to ground is 150Ω ±15Ω.
9. The transmitter or receiver should not be damaged
by connection to earth ground, short-circuiting or
cross connection to other lines.
10. No data errors should occur with ±2V common
mode change at either the transmitter/receiver or
±4V ground potential difference between transmit-
ter and receiver.
Cable Termination
Each end of the cable connected to an LTC1346A must be
terminated by an external Y- or ∆-resistor network for
proper operation. The Y-termination has two series con-
nected 50Ω resistors and a 125Ω resistor connected
between ground and the center tap of the two 50Ω resistors
as shown in Figure 6.
The alternative ∆-termination has a 120Ω resistor across
the twisted wires and two 300Ω resistors between each
wire and ground. Standard 1/8W, 5% surface mount
resistors can be used for the termination network. To
maintain the proper differential output swing, the resistor
tolerance must be 5% or better. A termination network
that combines all the resistors into an SO-14 package is
available from:
BI Technologies (Formerly Beckman Industrial)
Resistor Networks
4200 Bonita Place
Fullerton, CA 92635
http://www.bitechnologies.com
Phone: (714) 447-2357
FAX: (714) 447-2500
Part #: BI Technologies 627T500/1250 (SOIC)
899-5-500/1250 (DIP)
Figure 6. Y- and ∆-Termination Networks
50Ω
50Ω
125Ω
Y
LTC1346A • F06
300Ω
300Ω
120Ω
∆
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LTC1346A
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APPLICATIONS INFORMATION
WUUU
Theory of Operation
The transmitter outputs consist of complementary
switched-current sources as shown in Figure 7.
With a logic zero at the transmitter input, the inverting
output Z sources 11mA and the noninverting output Y
sinks 11mA. The differential transmitter output voltage is
then set by the termination resistors. With two differential
50Ω resistors at each end of the cable, the voltage is set to
(50Ω)(11mA) = 0.55V. With a logic 1 at the transmitter
input, output Z sinks 11mA and Y sources 11mA. The
common mode voltage of Y and Z is 0V when both current
sources are matched and there is no ground potential
difference between the cable terminations. The transmitter
current sources have a common mode range of ±2V, which
allows for a ground difference between cable terminations
of ±4V.
Each receiver input has a 30k resistance to ground and
requires external termination to meet the V.35 input imped-
ance specification. The receivers have an input hysteresis
of 50mV to improve noise immunity.
Three Select pins, S0, S1 and S2, configure the chip as
described in Function Tables. When the transmitters and
Figure 7. Simplified Transmitter Schematic
11mA
11mA
LTC1346A • F07
Y
Z
T
50Ω125Ω
50Ω
VCC
VEE
CHIP
BOUNDARY
receivers are OFF, all outputs are forced into high imped-
ance. The S0 pin can be used as receiver output enable.
In Shutdown mode, I
CC
drops to 1µA with all transmitters
and receivers OFF. When the LTC1346A is enabled from
Shutdown the transmitters and receivers require 2µs to
stabilize.
Complete V.35 Port
Figure 8 shows the schematic of a complete surface
mounted, ±5V DTE and DCE V.35 port using only three ICs
and six capacitors per port. The LTC1346A is used to
transmit the clock and data signals and the LT1134A to
transmit the control signals. If test signals 140, 141 and
142 are not used, the transmitter inputs should be tied
to V
CC
.
RS422/RS485 Applications
The receivers on the LTC1346A can be used for RS422
and RS485 applications. Using the test circuit in Figure 9,
the LTC1346A receivers are able to successfully extract
the data stream from the common mode voltage, meeting
RS422 and RS485 requirements as shown in Figures 10
and 11.
9
LTC1346A
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APPLICATIONS INFORMATION
WUUU
Figure 8. Complete Single ±5V V.35 Interface
DTE DCE
VCC1
5V
VEE1
–5V
0.1µF
12
4
1
2
24
23
12P
S
U
W
Y
X
V
T
R
10
11
16
15
0.1µF
DX
LTC1346A LTC1346A
BI
627T500/
1250
(SOIC)
VCC2
5V
VEE2
–5V
0.1µF
21
0.1µF
RX
T
TXD (103)
SCTE (113)
TXC (114)
RXC (115)
RXD (104)
GND (102)
CABLE SHIELD
5
3
AA
P
S
U
W
Y
X
V
T
R
BB
AA
AA
4
22
21
10
11
9
14
13
DX RX
T
9
14
13
18
17
1
4
2
24
23
T
10
12
11
16
15
878
12
3
5
4
22
21
T
H H
8
11
10
9
14
13
7
33
7
5
6
6
20
19
T
BI
627T500/
1250
(SOIC)
T
T
T
T
T
RX
RX
RX
VCC1
8127
VCC2
DTR (108)
DX
DX
DX
4
0.2µF
3 22
0.2µF0.2µF 0.2µF
0.1µF
23
241
2
21
0.1µFLT1134A LT1134A
4322
0.1µF
23
241
0.1µF
19
13 13
LTC1346A • TA08
50Ω
=125Ω
T
50Ω
DX
DX
17
OPTIONAL SIGNALS
DX
15 DX
20 RX
18 RX
16 RX
14
5
7
9
11
6
8
10
12
20
18
16
14
21
19
17
15
6
8
10
12
5
7
9
11
RX
RX
RX
RX
RX
DX
DX
DX
DX
C C
RTS (105)
E E
DSR (107)
D D
CTS (106)
F F
DCD (109)
NN NN
TM (142)
N N
RDL (140)
L L
LLB (141)
ISO 2593
34-PIN DTE/DCE
INTERFACE CONNECTOR
ISO 2593
34-PIN DTE/DCE
INTERFACE CONNECTOR
10
LTC1346A
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APPLICATIONS INFORMATION
WUUU
LTC485
7V TO –7V
GND POTENTIAL DIFFERENCE
VCC1
5V
100
9
100
9
AA
BB
GND
LTC1346A • F09
LTC1346A
VCC2
5V
GND
TTL
IN
TTL
OUT
VEE
–5V
–+
Figure 9. RS422/RS485 Receiver Interface
LTC1346 • F10
RECEIVER
OUTPUT
5V/DIV
A
B–10V
–5V
0V
0V
5V
RECEIVER
INPUT
5V/DIV RECEIVER
OUTPUT
5V/DIV
15V
5V
0V
LTC1346 • F11
10V
5V
0V
A
B
RECEIVER
INPUT
5V/DIV
Figure 10. –7V Common Mode Figure 11. 12V Common Mode
Multiprotocol Application
The LTC1346A can be used in multiprotocol applications
where V.35, RS232 and RS422 (used in RS530, RS449
among others) signals may appear at the same port. The
LTC1346A switched current source driver is not compatible
with RS232 or RS422. However, the outputs when disabled
can share lines with RS232 drivers with a Shutdown feature
such as the LT1030 and RS422 drivers with a disable
feature such as the LTC486/LTC487 (Figure 12a).
The LTC1346A driver will not be damaged or load the
shared lines when disabled. The LTC1346A receiver can
receive V.35, RS232 and RS422 signals as shown in Figure
12b. The LTC1346A receiver is directly compatible with
V.35 and RS422. For RS232 signal, the noninverting input
of the receiver should be grounded. Because the line
termination for each of the protocols is different, some
form of termination switching should be included, either
the connector (as shown in Figures 12a and 12b) or on the
PCB.
11
LTC1346A
1346afa
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
APPLICATIONS INFORMATION
WUUU
Figure 12a. Multiprotocol Transmitter
LT1030
LTC487
LTC1346A
CONNECTOR
125Ω
50Ω
V.35 DIFFERENTIAL
CONNECTION WITH
TERMINATION
RS422
DIFFERENTIAL
CONNECTION
RS232
CONNECTION
NO CONNECTION
1346A F12a
LOGIC
INPUT
50Ω
Figure 12b. Multiprotocol Receiver
LTC1346A
1346A F12b
LOGIC
OUTPUT
125Ω100Ω5k
50Ω
50Ω
CONNECTOR
V.35 DIFFERENTIAL
CONNECTION WITH
TERMINATION
RS422 DIFFERENTIAL
CONNECTION WITH
TERMINATION
RS232
CONNECTION WITH
TERMINATION
12
LTC1346A
1346afa
U
PACKAGE DESCRIPTIO
SW Package
24-Lead Plastic Small Outline (Wide 0.300)
(LTC DWG # 05-08-1620)
RELATED PARTS
Dimensions in inches (millimeters) unless otherwise noted.
LW/TP 1002 1K REV A • PRINTED IN USA
LINEAR TE CHNO LO G Y CO R P O R ATIO N 1995
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear.com
PART NUMBER DESCRIPTION COMMENTS
LT1134A 5V Only, 4-Driver/4-Receiver RS232 Transceiver Forms Complete V.35 Interface with LTC1346A
LTC1334 5V Only, Configurable RS232/RS485 Transceiver Includes On-Chip Charge Pump
LTC1344/LTC1344A Multiprotocol Cable Terminator Software Selectable, Supports V.35, V.36, V.28, EIA-530, EIA-530-A,
RS449, X.21
LTC1544 4-Driver, 4-Receiver Multiprotocol Transceiver 5V Supply, Supports V.35, V.36, V.28, EIA-530, EIA-530-A,
RS449, X.21
LTC1545 5-Driver, 5-Receiver Multiprotocol Transceiver 5V Supply, Supports V.35, V.36, V.28, EIA-530, EIA-530-A,
RS449, X.21
LTC1546 3-Driver, 3-Receiver Multiprotocol Transceiver 5V Supply, Supports V.35, V.36, V.28, EIA-530, EIA-530-A,
with Termination RS449, X.21
LTC2844 3.3V, 4-Driver, 4-Receiver Multiprotocol Transceiver 3.3V Supply, Supports V.35, V.36, V.28, EIA-530, EIA-530-A,
RS449, X.21
LTC2845 3.3V, 5-Driver, 5-Receiver Multiprotocol Transceiver 3.3V Supply, Supports V.35, V.36, V.28, EIA-530, EIA-530-A,
RS449, X.21
LTC2846 3.3V, 3-Driver, 3-Receiver Multiprotocol Transceiver 3.3V Supply, Supports V.35, V.36, V.28, EIA-530, EIA-530-A,
with Termination RS449, X.21
S24 (WIDE) 0502
NOTE 3
.598 – .614
(15.190 – 15.600)
NOTE 4
22 21 20 19 18 17 16 15
12345678
.394 – .419
(10.007 – 10.643)
910
1314
11 12
N/2
2324
N
.037 – .045
(0.940 – 1.143)
.004 – .012
(0.102 – 0.305)
.093 – .104
(2.362 – 2.642)
.050
(1.270)
BSC .014 – .019
(0.356 – 0.482)
TYP
0° – 8° TYP
NOTE 3
.009 – .013
(0.229 – 0.330)
.016 – .050
(0.406 – 1.270)
.291 – .299
(7.391 – 7.595)
NOTE 4
× 45°
.010 – .029
(0.254 – 0.737)
.420
MIN
.325 ±.005
RECOMMENDED SOLDER PAD LAYOUT
.045 ±.005
N
123 N/2
.050 BSC
.030 ±.005
TYP
.005
(0.127)
RAD MIN
INCHES
(MILLIMETERS)
NOTE:
1. DIMENSIONS IN
2. DRAWING NOT TO SCALE
3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS.
THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS
4. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
