LTC1345
Single Supply
V.35 Transceiver
FEATURES
s
s
s
s
DESCRIPTIO
s
s
s
s
s
Single Chip Provides All V.35 Differential Clock
and Data Signals
Operates From Single 5V Supply
Software Selectable DTE or DCE Configuration
Transmitters and Receivers Will Withstand
Repeated
±10kV
ESD Pulses
Shutdown Mode Reduces I
CC
to 1µA Typ
10MBaud Transmission Rate
Transmitter Maintains High Impedance When
Disabled, Shut Down, or with Power Off
Meets CCITT V.35 Specification
Transmitters are Short-Circuit Protected
The LTC
®
1345 is a single chip transceiver that provides the
differential clock and data signals for a V.35 interface from
a single 5V supply. Combined with an external resistor
termination network and an LT
®
1134A RS232 transceiver
for the control signals, the LTC1345 forms a complete low
power DTE or DCE V.35 interface port operating from a
single 5V supply.
The LTC1345 features three current output differential
transmitters, three differential receivers, and a charge
pump. The transceiver can be configured for DTE or DCE
operation or shut down using two Select pins. In the
Shutdown mode, the supply current is reduced to 1µA.
The transceiver operates up to 10Mbaud. All transmitters
feature short-circuit protection and a Receiver Output
Enable pin allows the receiver outputs to be forced into a
high impedance state. Both transmitter outputs and re-
ceiver inputs feature
±10kV
ESD protection. The charge
pump features a regulated V
EE
output using three external
1µF capacitors.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
s
s
s
Modems
Telecommunications
Data Routers
TYPICAL APPLICATIO
1µF
V
CC1
5V
3
1µF
6
LTC1345
1µF
4
2
1
28
Clock and Data Signals for V.35 Interface
1µF
1µF
V
CC2
5V
3
LTC1345
1µF
12
DTE
27
BI
1µF
627T500/1250
1
2
3
4
14
13
12
11
10
9
7
8
GND (102)
8
T
T
RXD (104)
T
T
RXC (115)
T
T
TXC (114)
T
T
SCTE (113)
T
BI
627T500/1250
TXD (103)
T
DCE
28
27
1µF
12
11
10
9
1
2
3
4
5
6
7
18
17
16
15
26
25
24
23
22
21
5
9
V
CC2
10
14
DX
8
DX
7
DX
6
RX
13
RX
1
2
4
26
DX
25
24
7
DX
23
20
11
RX
19
18
12
RX
17
16
13
RX
15
5
9
10
V
CC1
14
U
50Ω
T
=
50Ω
BI TECHNOLOGIES
627T500/1250 (SOIC) OR
899TR50/125 (DIP)
LTC1345 • TA01
U
U
125Ω
1
LTC1345
ABSOLUTE
(Note 1)
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
C2
+
1
C1
+
2
V
CC
3
C1
–
4
GND 5
T1 6
T2 7
T3 8
S1 9
S2 10
R3 11
R2 12
R1 13
OE 14
NW PACKAGE
28-LEAD PDIP
28 C2
–
27 V
EE
26 Y1
25 Z1
24 Y2
23 Z2
22 Y3
21 Z3
20 B3
19 A3
18 B2
17 A2
16 B1
15 A1
SW PACKAGE
28-LEAD PLASTIC SO
Supply Voltage, V
CC
.................................................. 6V
Input Voltage
Transmitters ........................... – 0.3V to (V
CC
+ 0.3V)
Receivers ............................................... – 18V to 18V
S1, S2, OE ............................... – 0.3V to (V
CC
+ 0.3V)
Output Voltage
Transmitters .......................................... – 18V to 18V
Receivers ................................ – 0.3V to (V
CC
+ 0.3V)
V
EE
........................................................ – 10V to 0.3V
Short-Circuit Duration
Transmitter Output ..................................... Indefinite
Receiver Output .......................................... Indefinite
V
EE
................................................................. 30 sec
Operating Temperature Range
Commercial ............................................ 0°C to 70°C
Industrial ........................................... – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART
NUMBER
LTC1345CNW
LTC1345CSW
LTC1345INW
LTC1345ISW
THREE V.35 TRANSMITTERS AND THREE RECEIVERS
T
JMAX
= 125°C,
θ
JA
= 56°C/W (NW)
T
JMAX
= 125°C,
θ
JA
= 65°C/W (SW)
Consult factory for Military grade parts.
DC ELECTRICAL CHARACTERISTICS
SYMBOL
V
OD
V
OC
I
OH
I
OL
I
OZ
R
O
V
TH
∆V
TH
I
IN
R
IN
V
OH
V
OL
I
OSR
I
OZR
V
IH
V
IL
I
IN
I
CC
PARAMETER
Transmitter Differential Output Voltage
Transmitter Common-Mode Output Voltage
Transmitter Output High Current
Transmitter Output Low Current
Transmitter Output Leakage Current
Transmitter Output Impedance
Differential Receiver Input Threshold Voltage
Receiver Input Hysterisis
Receiver Input Current (A, B)
Receiver Input Impedance
Receiver Output High Voltage
Receiver Output Low Voltage
Receiver Output Short-Circuit Current
Receiver Three-State Output Current
Logic Input High Voltage
Logic Input Low Voltage
Logic Input Current
V
CC
Supply Current
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V
±5%
(Notes 2, 3), unless otherwise specified.
CONDITIONS
Figure 1, – 4V
≤
V
OS
≤
4V
Figure 1, V
OS
= 0V
V
Y, Z
= 0V
V
Y, Z
= 0V
S1 = S2 = 0V, – 5V
≤
V
Y, Z
≤
5V
– 2V
≤
V
Y, Z
≤
2V
– 7V
≤
(V
A
+ V
B
)/2
≤
7V
– 7V
≤
(V
A
+ V
B
)/2
≤
7V
– 7V
≤
V
A, B
≤
7V
– 7V
≤
V
A, B
≤
7V
I
O
= 4mA, V
B, A
= 0.2V
I
O
= 4mA, V
B, A
= – 0.2V
0V
≤
V
O
≤
V
CC
S1 = S2 = 0V, 0V
≤
V
O
≤
V
CC
T, S1, S2, OE
T, S1, S2, OE
T, S1, S2, OE
Figure 1, V
OS
= 0, S1 = S2 = HIGH
No Load, S1 = S2 = HIGH
Shutdown, S1 = S2 = 0V
No Load, S1 = S2 = HIGH
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
MIN
0.44
– 0.6
– 12.6
9.4
TYP
0.55
0
– 11
11
±1
100
25
50
30
4.5
0.2
MAX
0.66
0.6
– 9.4
12.6
±100
200
0.4
17.5
3
7
2
0.4
85
±10
0.8
±10
170
30
100
V
EE
V
EE
Voltage
118
19
1
– 5.5
UNITS
V
V
mA
mA
µA
kΩ
mV
mV
mA
kΩ
V
V
mA
µA
V
V
µA
mA
mA
µA
V
2
U
W
U
U
W W
W
LTC1345
AC ELECTRICAL CHARACTERISTICS
SYMBOL
t
R
, t
F
t
PLH
t
PHL
t
SKEW
t
PLH
t
PHL
t
SKEW
t
ZL
t
ZH
t
LZ
t
HZ
f
OSC
BR
MAX
PARAMETER
Transmitter Rise or Fall Time
Transmitter Input to Output
Transmitter Input to Output
Transmitter Output to Output
Receiver Input to Output
Receiver Input to Output
Differential Receiver Skew, t
PLH
– t
PHL
Receiver Enable to Output LOW
Receiver Enable to Output HIGH
Receiver Disable From LOW
Receiver Disable From HIGH
Charge Pump Oscillator Frequency
Maximum Data Rate (Note 4)
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V
±5%
(Notes 2, 3), unless otherwise specified.
CONDITIONS
Figures 1 and 3, V
OS
= 0V
Figures 1 and 3, V
OS
= 0V
Figures 1 and 3, V
OS
= 0V
Figures 1 and 3, V
OS
= 0V
Figures 1 and 4, V
OS
= 0V
Figures 1 and 4, V
OS
= 0V
Figures 1 and 4, V
OS
= 0V
Figures 2 and 5, C
L
= 15pF, S1 Closed
Figures 2 and 5, C
L
= 15pF, S2 Closed
Figures 2 and 5, C
L
= 15pF, S1 Closed
Figures 2 and 5, C
L
= 15pF, S2 Closed
MIN
q
q
q
q
q
q
q
q
q
q
10
TYP
7
25
25
0
49
52
3
40
35
30
35
200
15
MAX
40
70
70
100
100
70
70
70
70
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
kHz
Mbaud
Note 1:
The absolute maximum ratings are those values beyond which the
safety of the device cannot be guaranteed.
Note 2:
All currents into device pins are termed positive; all currents out of
device pins are termed negative. All voltages are referenced to device
ground unless otherwise specified.
Note 3:
All typicals are given for V
CC
= 5V, C1 = C2 = C3 = 1µF ceramic
capacitors and T
A
= 25°C.
Note 4:
Maximum data rate is specified for NRZ data encoding scheme.
The maximum data rate may be different for other data encoding schemes.
Data rate is guaranteed by correlation and is not tested.
TYPICAL PERFOR A CE CHARACTERISTICS
Transmitter Output Current
vs Temperature
13
V
CC
= 5V
OUTPUT
CURRENT (mA)
12
OUTPUT
CURRENT (mA)
11
TIME (ns)
10
9
–50 –25
0
75
50
25
TEMPERATURE (˚C)
U W
100
LTC1345 • TPC01
Transmitter Output Current
vs Output Voltage
13
T
A
= 25°C
V
CC
= 5V
12
Transmitter Output Skew
vs Temperature
20
V
CC
= 5V
15
11
10
10
5
125
9
–2.0 –1.5 –1.0 –0.5 0 0.5 1.0
OUTPUT VOLTAGE (V)
1.5
2.0
0
–50 –25
0
75
50
25
TEMPERATURE (˚C)
100
125
LTC1345 • TPC02
LTC1345 • TPC03
3
LTC1345
TYPICAL PERFOR A CE CHARACTERISTICS
Receiver
t
PLH
– t
PHL
vs Temperature
20
V
CC
= 5V
15
CURRENT (mA)
NO LOAD
100
20
10
VOLTAGE (V)
TIME (ns)
5
0
–50 –25
0
75
50
25
TEMPERATURE (˚C)
Transmitter Output Waveforms
INPUT
5V/DIV
OUTPUT
0.2V/DIV
PI FU CTIO S
C2
+
(Pin 1):
Capacitor C2 Positive Terminal.
C1
+
(Pin 2):
Capacitor C1 Positive Terminal.
V
CC
(Pin 3):
Positive Supply, 4.75
≤
V
CC
≤
5.25V.
C1
–
(Pin 4):
Capacitor C1 Negative Terminal.
GND (Pin 5):
Ground. The positive terminal of C3 is
connected to ground.
T1 (Pin 6):
Transmitter 1 Input.
T2 (Pin 7):
Transmitter 2 Input.
T3 (Pin 8):
Transmitter 3 Input.
S1 (Pin 9):
Select Input 1.
S2 (Pin 10):
Select Input 2.
R3 (Pin 11):
Receiver 3 Output.
R2 (Pin 12):
Receiver 2 Output.
R1 (Pin 13):
Receiver 1 Output.
OE (Pin 14):
Receiver Output Enable.
A1 (Pin 15):
Receiver 1 Inverting Input.
B1 (Pin 16):
Receiver 1 Noninverting Input.
A2 (Pin 17):
Receiver 2 Inverting Input.
B2 (Pin 18):
Receiver 2 Noninverting Input.
A3 (Pin 19):
Receiver 3 Inverting Input.
B3 (Pin 20):
Receiver 3 Noninverting Input.
Z3 (Pin 21):
Transmitter 3 Inverting Output.
4
U W
100
LTC1345 • TPC04
Supply Current vs Temperature
140
V
CC
= 5V
LOADED
120
25
CURRENT (mA)
–5.0
V
EE
Voltage vs Temperature
30
–4.5
V
CC
= 5V
–5.5
80
15
–6.0
125
60
–50 –25
0
75
50
25
TEMPERATURE (˚C)
100
10
125
–6.5
–50 –25
0
75
50
25
TEMPERATURE (˚C)
100
125
LTC1345 • TPC05
LTC1345 • TPC06
Receiver Output Waveforms
INPUT
0.2/DIV
OUTPUT
5V/DIV
LTC1345 • TPC07
LTC1345 • TPC08
U
U
U
LTC1345
PI FU CTIO S
Y3 (Pin 22):
Transmitter 3 Noninverting Output.
Z2 (Pin 23):
Transmitter 2 Inverting Output.
Y2 (Pin 24):
Transmitter 2 Noninverting Output
Z1 (Pin 25):
Transmitter 1 Inverting Output.
Y1 (Pin 26):
Transmitter 1 Noninverting Output.
V
EE
(Pin 27):
Charge Pump Output. Connected to negative
terminal of capacitor C3.
C2
–
(Pin 28):
Capacitor C2 Negative Terminal.
FU CTIO TABLES
Transmitter and Receiver Configuration
S1
0
1
0
1
S2
0
0
1
1
TX#
—
1, 2, 3
1, 2
1, 2, 3
RX#
—
1, 2
1, 2, 3
1, 2, 3
REMARKS
Shutdown
DCE Mode, RX3 Shut Down
DTE Mode, TX3 Shut Down
All Active
DTE or All ON
DTE or All ON
DCE
DCE
Disabled
INPUTS
CONFIGURATION S1 S2
DTE
DTE
DCE or All ON
DCE or All ON
Shutdown
0
0
1
1
0
1
1
X
X
0
T
0
1
0
1
X
Y1 AND Y2
0
1
0
1
Z
OUTPUTS
Z1 AND Z2
1
0
1
0
Z
Y3
Z
Z
0
1
Z
Z3
Z
Z
1
0
Z
Shutdown
X
X
1
1
X
0
1
1
0
0
X
0
Transmitter
TEST CIRCUITS
V
CC
Y
S1
50Ω
T
Y
V
OD
Z
A
50Ω
V
OC
= (V
Y
+ V
Z
)/2
Z
50Ω
125Ω
V
OS
50Ω
125Ω
B
R
OE
15pF
RECEIVER
OUTPUT
C
L
1k
Figure 1. V.35 Transmitter/Receiver Test Circuit
U
U
U
U
U
Receiver
INPUTS
CONFIGURATION S1 S2 OE
0
0
0
0
1
X
B–A
≥
0.2V
≤
– 0.2V
≥
0.2V
≤
– 0.2V
X
X
OUTPUTS
R1 AND R2
1
0
1
0
Z
Z
R3
1
0
Z
Z
Z
Z
S2
LTC1345 • F02
LTC1345 • F01
Figure 2. Receiver Output Enable/Disable Timing Test Load
5
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