Linear Technology LTC1345CSW, LTC1345CNW, LTC1345ISW, LTC1345INW Datasheet

FEATURES

■

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 ICC 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

LTC1345

Single Supply

V.35 Transceiver

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DESCRIPTIO

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.

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APPLICATIO S

■

Modems

■

Telecommunications

■

Data Routers

TYPICAL APPLICATIO

1µF

1µF 1µF1µF

V

CC1

5V

1µF

11

12

13

2

4

1

LTC1345 LTC1345

6

DX

7

DX

RX

RX

RX

10

14

9

V

CC1

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 re­ceiver inputs feature ±10kV ESD protection. The charge
pump features a regulated VEE output using three external
1µF capacitors.

, LTC and LT are registered trademarks of Linear Technology Corporation.

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Clock and Data Signals for V.35 Interface

DCEDTE

28

273

26

25
24

23
20

19
18

17
16

15
5

1µF

1

2
3

4

14

13
12

11
10

9
7

BI

627T500/1250

T

T T

T T

T T

T T

8

TXD (103)

SCTE (113)

TXC (114)

RXC (115)

RXD (104)

GND (102)

BI

627T500/1250

T

8

12

111817
10

9
1

2
3

4
5

6
7

1µF

16

15
26

25
24

23
22

21

1

28

2

4

RX

RX

DX

DX

DX

5

10 14

9

V

CC2

V

327

1µF

12

13

6

7

8

627T500/1250 (SOIC) OR

LTC1345 • TA01

CC2

5V

50Ω

=

T

50Ω

BI TECHNOLOGIES

899TR50/125 (DIP)

125Ω

1

LTC1345

PACKAGE/ORDER I FOR ATIO

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W

WWWU

ABSOLUTE AXI U RATI GS

(Note 1)

Supply Voltage, VCC.................................................. 6V

Input Voltage

Transmitters ........................... –0.3V to (VCC + 0.3V)

Receivers............................................... –18V to 18V

S1, S2, OE ............................... –0.3V to (VCC + 0.3V)

Output Voltage

Transmitters .......................................... –18V to 18V

Receivers................................ –0.3V to (VCC + 0.3V)

VEE........................................................ –10V to 0.3V

Short-Circuit Duration

Transmitter Output ..................................... Indefinite

Receiver Output.......................................... Indefinite

VEE................................................................. 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

TOP VIEW

+

1

C2

+

2

C1

3

V

CC

–

4

C1

5

GND

6

T1

7

T2

8

T3

9

S1

10

S2

11

R3

12

R2

13

R1

14

OE

NW PACKAGE

28-LEAD PDIP

THREE V.35 TRANSMITTERS AND THREE RECEIVERS

T

= 125°C, θ

JMAX

T

= 125°C, θ

JMAX

SW PACKAGE

28-LEAD PLASTIC SO

= 56°C/W (NW)

JA

= 65°C/W (SW)

JA

–

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

ORDER PART

NUMBER

LTC1345CNW
LTC1345CSW
LTC1345INW
LTC1345ISW

Consult factory for Military grade parts.

DC ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VCC = 5V ±5% (Notes 2, 3), unless otherwise specified.

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

I

CC

V

OD
OC

O
TH

TH

IN
OH
OL

IH
IL

EE

Transmitter Differential Output Voltage Figure 1, –4V ≤ VOS ≤ 4V ● 0.44 0.55 0.66 V
Transmitter Common-Mode Output Voltage Figure 1, VOS = 0V ● –0.6 0 0.6 V
Transmitter Output High Current V
Transmitter Output Low Current V
Transmitter Output Leakage Current S1 = S2 = 0V, –5V ≤ V
Transmitter Output Impedance –2V ≤ V

= 0V ● –12.6 –11 – 9.4 mA

Y, Z

= 0V ● 9.4 11 12.6 mA

Y, Z

≤ 5V ● ±1 ±100 µA

Y, Z

≤ 2V 100 kΩ

Y, Z

Differential Receiver Input Threshold Voltage –7V ≤ (VA + VB)/2 ≤ 7V ● 25 200 mV
Receiver Input Hysterisis –7V ≤ (VA + VB)/2 ≤ 7V 50 mV
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 S1 = S2 = 0V, 0V ≤ VO ≤ V

≤ 7V ● 0.4 mA

A, B

≤ 7V ● 17.5 30 kΩ

A, B

= 0.2V ● 3 4.5 V

B, A

= –0.2V ● 0.2 0.4 V

B, A

CC

CC

● 785mA

● ±10 µA

Logic Input High Voltage T, S1, S2, OE ● 2V
Logic Input Low Voltage T, S1, S2, OE ● 0.8 V
Logic Input Current T, S1, S2, OE ● ±10 µA
VCC Supply Current Figure 1, VOS = 0, S1 = S2 = HIGH ● 118 170 mA

No Load, S1 = S2 = HIGH
Shutdown, S1 = S2 = 0V

● 19 30 mA

● 1 100 µA

VEE Voltage No Load, S1 = S2 = HIGH –5.5 V

2

LTC1345

TEMPERATURE (˚C)

–50

TIME (ns)

25

LTC1345 • TPC03

10

5

–25 0 50

0

20

15

75 100 125

VCC = 5V

AC ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VCC = 5V ±5% (Notes 2, 3), unless otherwise specified.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

tR, 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

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.

Transmitter Rise or Fall Time Figures 1 and 3, VOS = 0V ● 740 ns
Transmitter Input to Output Figures 1 and 3, VOS = 0V ● 25 70 ns
Transmitter Input to Output Figures 1 and 3, VOS = 0V ● 25 70 ns
Transmitter Output to Output Figures 1 and 3, VOS = 0V 0 ns
Receiver Input to Output Figures 1 and 4, VOS = 0V ● 49 100 ns
Receiver Input to Output Figures 1 and 4, VOS = 0V ● 52 100 ns
Differential Receiver Skew, t

PLH

– t

PHL

Figures 1 and 4, VOS = 0V 3 ns
Receiver Enable to Output LOW Figures 2 and 5, CL = 15pF, S1 Closed ● 40 70 ns
Receiver Enable to Output HIGH Figures 2 and 5, CL = 15pF, S2 Closed ● 35 70 ns
Receiver Disable From LOW Figures 2 and 5, CL = 15pF, S1 Closed ● 30 70 ns
Receiver Disable From HIGH Figures 2 and 5, CL = 15pF, S2 Closed ● 35 70 ns
Charge Pump Oscillator Frequency 200 kHz
Maximum Data Rate (Note 4) ● 10 15 Mbaud

Note 3: All typicals are given for VCC = 5V, C1 = C2 = C3 = 1µF ceramic
capacitors and T

= 25°C.

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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.

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TYPICAL PERFOR A CE CHARACTERISTICS

Transmitter Output Current
vs Output Voltage

13

TA = 25°C

= 5V

V

CC

12

11

10

OUTPUT CURRENT (mA)

9

–1.5

–2.0

–0.5

–1.0

OUTPUT VOLTAGE (V)

OUTPUT CURRENT (mA)

Transmitter Output Current
vs Temperature

13

VCC = 5V

12

11

10

9

–25 0 50

–50

25

TEMPERATURE (˚C)

75 100 125

LTC1345 • TPC01

Transmitter Output Skew
vs Temperature

0.5

0

1.0

1.5

LTC1345 • TPC02

2.0

3

LTC1345

TEMPERATURE (˚C)

–50

VOLTAGE (V)

25

LTC1345 • TPC06

–5.5

–6.0

–25 0 50

–6.5

–4.5

–5.0

75 100 125

VCC = 5V

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TYPICAL PERFOR A CE CHARACTERISTICS

Receiver t
vs Temperature

20

VCC = 5V

15

10

TIME (ns)

5

0

–25 0 50

–50

– t

PLH

TEMPERATURE (˚C)



PHL

25

75 100 125

LTC1345 • TPC04

Transmitter Output Waveforms

INPUT

5V/DIV

OUTPUT

0.2V/DIV

Supply Current vs Temperature

140

VCC = 5V

120

100

CURRENT (mA)

80

60

–25 0 50

–50

LOADED

NO LOAD

25

TEMPERATURE (˚C)

30

25

CURRENT (mA)

20

15

75 100 125

LTC1345 • TPC05

10

Receiver Output Waveforms

INPUT

0.2/DIV

OUTPUT

5V/DIV

VEE Voltage vs Temperature

LTC1345 • TPC07

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PI FU CTIO S

C2+ (Pin 1):
C1+ (Pin 2): Capacitor C1 Positive Terminal.
VCC (Pin 3): Positive Supply, 4.75 ≤ VCC ≤ 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.

Capacitor C2 Positive Terminal.

LTC1345 • TPC08

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.

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