Page 1
FEATURES
■
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 ICC 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
U
APPLICATIO S
■
Modems
■
Telecommunications
■
Data Routers
LTC1346A
10Mbps DCE/DTE
V.35 Transceiver
U
DESCRIPTIO
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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
V
EE1
–5V
0.1mF
+
V
CC1
5V
1
2
0.1mF
+
V
CC1
LTC1346A LTC1346ABI
4
DX
5
DX
9
10
11
7
8
RX
RX
RX
12
U
Clock and Data Signals for V.35 Interface
DTE DCE
BI
627T500/1250
T
12
111615
10
91413
1
22423
3
42221
5
62019
78
24
23
22
21
18
17
16
15
14
13
3
627T500/1250
1
T
2
3
T T
4
14
T T
13
12
T T
11
10
T T
9
78
TXD (103)
SCTE (113)
TXC (114)
RXC (115)
RXD (104)
GND (102)
1
2
RX
RX
DX
DX
DX
3
10
11
4
5
6
7
8
12
V
5V
+
0.1mF
T
V
CC2
BI TECHNOLOGIES
627T500/1250 (SOIC)
CC2
50
=
50
+
W
W
0.1mF
125
W
LTC1346 • TA01
V
–5V
EE2
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Page 2
LTC1346A
A
W
O
LUTEXI TIS
S
A
WUW
U
ARB
G
(Note 1)
Supply Voltage
.................................................................... 6.5V
V
CC
VEE................................................................... –6.5V
Input Voltage
Transmitters ........................... –0.3V to (V
+ 0.3V)
CC
Receivers............................................... –18V to 18V
S0, S1, S2 ............................... –0.3V to (VCC + 0.3V)
Output Voltage
Transmitters .......................................... – 18V to 18V
Receivers................................ – 0.3V to (VCC + 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
WU
/
PACKAGE
1
V
EE
2
V
CC
3
GND
4
T1
5
T2
6
T3
7
S1
8
S2
9
R3
10
R2
11
R1
12
S0
24-LEAD PLASTIC SO WIDE
T
JMAX
Consult LTC Marketing for parts specified with wider operating temperature
ranges.
O
TOP VIEW
SW PACKAGE
= 150°C, θ
RDER I FOR ATIO
ORDER PART
NUMBER
24
Y1
23
= 85°C/W
JA
Z1
22
Y2
21
Z2
20
Y3
19
Z3
18
A3
17
B3
16
A2
15
B2
14
A1
13
B1
LTC1346ACSW
U
DC ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating
temperature range. VCC = 5V ±5%, VEE = –5V ±5% (Note 2)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
V
I
OH
I
OL
I
OZ
R
V
∆V
I
IN
R
V
V
I
OSR
I
OZR
V
V
I
IN
OD
OC
O
TH
IN
OH
OL
IH
IL
Transmitter Differential Output Voltage –4V ≤ VOS ≤ 4V (Figure 1) ● 0.44 0.55 0.66 V
Transmitter Common Mode Output Voltage VOS = 0V (Figure 1) ● –0.6 0 0.6 V
Transmitter Output High Current V
Transmitter Output Low Current V
Transmitter Output Leakage Current –5V ≤ V
Transmitter Output Impedance – 2V ≤ V
Differential Receiver Input Threshold Voltage – 7V ≤ (VA + VB)/2 ≤ 12V ● 25 200 mV
Receiver Input Hysterisis – 7V ≤ (VA + VB)/2 ≤ 12V 50 mV
TH
Receiver Input Current (A, B) – 7V ≤ V
Receiver Input Impedance – 7V ≤ V
Receiver Output High Voltage IO = 4mA, V
Receiver Output Low Voltage IO = 4mA, V
Receiver Output Short-Circuit Current 0V ≤ VO ≤ V
Receiver Three-State Output Current S0 = VCC, 0V ≤ VO ≤ V
Logic Input High Voltage T, S0, S1, S2 ● 2V
Logic Input Low Voltage T, S0, S1, S2 ● 0.8 V
Logic Input Current T, S0, S1, S2 ● ±10 µA
= 0V ● –12.6 – 11 – 9.4 mA
Y, Z
= 0V ● 9.4 11 12.6 mA
Y, Z
≤ 5V, S1 = S2 = 0V ±1 ± 20 µA
Y, Z
≤ 2V 100 kΩ
Y, Z
≤ 12V ● 0.7 mA
A, B
≤ 12V ● 17.5 30 kΩ
A, B
= 0.2V ● 3 4.5 V
A, B
= –0.2V ● 0.2 0.4 V
A, B
CC
CC
● ±100 µA
● 74085 mA
● ±10 µA
2
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LTC1346A
TEMPERATURE (˚C)
–50
TIME (ns)
25
1346A G03
10
5
–25 0 50
0
20
15
75 100 125
VCC = 5V
V
EE
= –5V
AC ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating
temperature range. VCC = 5V ±5%, VEE = –5V ±5% (Note 2)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
CC
I
EE
tr, t
t
PLH
t
PHL
t
SKEW
t
PLH
t
PHL
t
SKEW
t
ZL
t
ZH
t
LZ
t
HZ
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.
VCC Supply Current VOS = 0V, S0 = Low, S1 = S2 = High (Figure 1) ● 40 50 mA
No Load, S0 = Low, S1 = S2 = High
Shutdown, S0 = V
S1 = S2 = 0V ● 0.1 100 µA
CC,
● 6 9 mA
VEE Supply Current VOS = 0V, S0 = Low, S1 = S2 = High (Figure 1) ● –40 –50 mA
No Load, S0 = Low, S1 = S2 = High
Shutdown, S0 = V
Transmitter Rise or Fall Time VOS = 0V (Figures 1, 3) ● 740 ns
f
S1 = S2 = 0V ● –0.1 – 100 µA
CC,
● –6 –9 mA
Transmitter Input to Output VOS = 0V (Figures 1, 3) ● 25 70 ns
Transmitter Input to Output VOS = 0V (Figures 1, 3) ● 30 70 ns
Transmitter Output to Output VOS = 0V (Figures 1, 3) 5 ns
Receiver Input to Output VOS = 0V (Figures 1, 4) ● 50 100 ns
Receiver Input to Output VOS = 0V (Figures 1, 4) ● 55 100 ns
Differential Receiver Skew, t
PLH
– t
V
PHL
= 0V (Figures 1, 4) 5 ns
OS
Receiver Enable to Output Low (Active Mode) CL = 15pF, SW1 Closed (Figures 2, 5) ● 40 70 ns
Receiver Enable to Output Low CL = 15pF, SW1 Closed (Figures 2, 5) 2 µs
(from Shutdown, Note 3)
Receiver Enable to Output High (Active Mode) CL = 15pF, SW2 Closed (Figures 2, 5) ● 35 70 ns
Receiver Enable to Output High CL = 15pF, SW2 Closed (Figures 2, 5) 2 µs
(from Shutdown, Note 3)
Receiver Disable from Low CL = 15pF, SW1 Closed (Figures 2, 5) ● 30 70 ns
Receiver Disable from High CL = 15pF, SW2 Closed (Figures 2, 5) ● 35 70 ns
Note 3: Receiver enable to output valid high or low from Shutdown is
typically 2µs.
UW
TYPICAL PERFOR A CE CHARACTERISTICS
Transmitter Output Current
vs Temperature
13
VCC = 5V
= –5V
V
EE
12
11
10
OUTPUT CURRENT (mA)
9
–25 0 50
–50
25
TEMPERATURE (˚C)
75 100 125
1346A G01
Transmitter Output Current
vs Output Voltage
13
TA = 25°C
= 5V
V
CC
= –5V
V
EE
12
11
10
OUTPUT CURRENT (mA)
9
–2.0
–1.5
–1.0
–0.5
OUTPUT VOLTAGE (V)
0
0.5
1.0
1.5
1346A G02
Transmitter Output Skew
vs Temperature
2.0
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LTC1346A
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
VCC = 5V
V
EE
= –5V
UW
TYPICAL PERFOR A CE CHARACTERISTICS
Receiver t
PLH
– t
PHL
vs Temperature ICC Supply Current vs Temperature
20
15
10
TIME (ns)
5
0
–50
VCC = 5V
= –5V
V
EE
–25 0 50
25
TEMPERATURE (˚C)
75 100 125
1346A G04
45
40
35
CURRENT (mA)
30
25
–25 0 50
–50
LOADED
NO LOAD
25
TEMPERATURE (˚C)
Receiver Output WaveformsTransmitter Output Waveforms
INPUT
5V/DIV
OUTPUT
0.2V/DIV
INPUT
0.2V/DIV
OUTPUT
5V/DIV
VCC = 5V
= –5V
V
EE
75 100 125
1346A G05
7.5
7.0
CURRENT (mA)
6.5
6.0
5.5
IEE Supply Current vs Temperature
Receiver Enable from Shutdown
INPUT A–B
1V/DIV
INPUT S0
5V/DIV
OUTPUT
5V/DIV
PIN FUNCTIONS
VEE (Pin 1):
VCC (Pin 2): Positive Supply, 4.75V ≤ VCC ≤ 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
1346A G07 1346A G08 1346A G09
UUU
Negative Supply, –4.75V ≥ VEE ≥ –5.25V
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
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LTC1346A
U
U
FU CTIO TABLES
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
Receiver
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
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
INPUTS OUTPUTS
TEST CIRCUITS
Y
125Ω
50Ω
50Ω
A
R
B
15pFS0
LTC1346A • F01
Y
T
Z
50Ω
125Ω
V
OD
50Ω
Z
V
OS
VOC = (VY + VZ)/2
Figure 1. V.35 Transmitter/Receiver Test Circuit
V
CC
SW1
RECEIVER
OUTPUT
1k
C
L
SW2
LTC1346A • F02
Figure 2. Receiver Output Enable and Disable Timing Test Load
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LTC1346A
UW
W
SWITCHI G TI E WAVEFOR S
Y – Z
A – B
–VOD/2
T
V
–V
VOD/2
V
R
V
3V
0V
O
O
Z
V
Y
O
Figure 3. V.35 Transmitter Propagation Delays
OH
OL
1.5V
t
10%
0V
t
PLH
50%
f = 1MHz: t
PLH
f = 1MHz: t
90%
t
r
t
SKEW
≤ 10ns: tf ≤ 10ns
r
1.5V
≤ 10ns: tf ≤ 10ns
r
V
= V(Y) – V(Z)
DIFF
1/2 V
O
INPUT
OUTPUT
1.5V
t
90%
0V
t
PHL
PHL
50%
10%
t
f
t
LTC1346A • F03
SKEW
1.5V
LTC1346A • F04
Figure 4. V.35 Receiver Propagation Delays
3V
S0
0V
5V
R
V
OL
V
OH
R
0V
1.5V
f = 1MHz: t
t
ZL
1.5V
t
ZH
1.5V
≤ 10ns: tf ≤ 10ns
r
OUTPUT NORMALLY LOW
OUTPUT NORMALLY HIGH
1.5V
t
t
LZ
0.5V
HZ
0.5V
LTC1346A • F05
Figure 5. Receiver Enable and Disable Times
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LTC1346A
U
WUU
APPLICATIONS INFORMATION
Review of CCITT Recommendation V.35
Electrical Specifications
V.35 is a CCITT recommendation for synchronous data
transmission via modems. Appendix 2 of the recommendation 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 terminals and ground is 150Ω ±15Ω.
4. When terminated by a 100Ω resistive load, the terminal-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.
10. No data errors should occur with ±2V common
mode change at either the transmitter/receiver or
±4V ground potential difference between transmitter 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 connected 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:
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.
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)
50Ω
125Ω
50Ω
Y
300Ω
120Ω
300Ω
∆
LTC1346A • F06
Figure 6. Y- and ∆-Termination Networks
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LTC1346A
U
WUU
APPLICATIONS INFORMATION
T
Figure 7. Simplified Transmitter Schematic
11mA
11mA
CHIP
BOUNDARY
Y
Z
50Ω
50Ω
125Ω
LTC1346A • F07
V
CC
V
EE
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 impedance 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
receivers are OFF, all outputs are forced into high impedance. The S0 pin can be used as receiver output enable.
In Shutdown mode, ICC 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 VCC.
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.
8
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Page 9
LTC1346A
V
CC1
5V
V
EE1
–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)
V
CC2
5V
V
EE2
–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
8
7
8
12
3
5
4
22
21
T
H H
8
11
10
9
14
13
7
3
3
7
5
6
6
20
19
T
BI
627T500/
1250
(SOIC)
T
T
T
T
T
RX
RX
RX
V
CC1
8127
V
CC2
DTR (108)
DX
DX
DX
4
0.2µF
3 22
0.2µF
0.2µF 0.2µF
0.1µF
23
241
2
21
0.1µF
LT1134A 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
U
WUU
APPLICATIONS INFORMATION
DTE DCE
Figure 8. Complete Single ±5V V.35 Interface
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LTC1346A
U
WUU
APPLICATIONS INFORMATION
V
CC1
5V
AA
LTC485
B
GND
TTL
IN
Figure 9. RS422/RS485 Receiver Interface
RECEIVER
OUTPUT
5V/DIV
RECEIVER
INPUT
5V/DIV
B
A
100
9
+
–
7V TO –7V
GND POTENTIAL DIFFERENCE
5V
0V
0V
–5V
–10V
RECEIVER
INPUT
5V/DIV
RECEIVER
OUTPUT
5V/DIV
100
A
B
9
B
V
CC2
5V
LTC1346A
GND
V
EE
–5V
LTC1346A • F09
TTL
OUT
15V
10V
5V
0V
5V
0V
LTC1346 • F10
Figure 10. –7V 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).
LTC1346 • F11
Figure 11. 12V Common Mode
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.
10
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Page 11
LTC1346A
U
WUU
APPLICATIONS INFORMATION
LT1030
LTC487
LTC1346A
LOGIC
INPUT
V.35 DIFFERENTIAL
CONNECTION WITH
TERMINATION
50Ω
125Ω
CONNECTOR
50Ω
RS422
DIFFERENTIAL
CONNECTION
RS232
CONNECTION
NO CONNECTION
1346A F12a
LOGIC
OUTPUT
LTC1346A
Figure 12a. Multiprotocol Transmitter
V.35 DIFFERENTIAL
CONNECTION WITH
TERMINATION
50Ω
125Ω
CONNECTOR
50Ω
Figure 12b. Multiprotocol Receiver
RS422 DIFFERENTIAL
CONNECTION WITH
TERMINATION
100Ω 5k
RS232
CONNECTION WITH
TERMINATION
1346A F12b
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
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11
Page 12
LTC1346A
PACKAGE DESCRIPTIO
.030 ±.005
TYP
N
U
Dimensions in inches (millimeters) unless otherwise noted.
SW Package
24-Lead Plastic Small Outline (Wide 0.300)
(LTC DWG # 05-08-1620)
.050 BSC
.045 ±.005
22 21 20 19 181716 15
2324
.598 – .614
(15.190 – 15.600)
NOTE 4
1314
.420
MIN
RECOMMENDED SOLDER PAD LAYOUT
.005
(0.127)
RAD MIN
.009 – .013
(0.229 – 0.330)
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)
RELATED PARTS
.325 ±.005
123 N/2
.291 – .299
(7.391 – 7.595)
NOTE 4
.010 – .029
(0.254 – 0.737)
NOTE 3
INCHES
(MILLIMETERS)
× 45°
.016 – .050
(0.406 – 1.270)
0° – 8° TYP
NOTE 3
.093 – .104
(2.362 – 2.642)
(1.270)
N
1
.050
BSC
(0.356 – 0.482)
2345
.014 – .019
TYP
6
78
910
11 12
(10.007 – 10.643)
N/2
.037 – .045
(0.940 – 1.143)
.004 – .012
(0.102 – 0.305)
.394 – .419
S24 (WIDE) 0502
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
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LW/TP 1002 1K REV A • PRINTED IN USA
LINE AR TE CHNO LOGY CORPORAT IO N 1995
12
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
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