SN55109A, SN55110A

SN75109A, SN75110A, SN75112

DUAL LINE DRIVERS

SLLS106B – DECEMBER 1975 – REVISED MAY 1995

2–9

POST OFFICE BOX 655303

APPLICATION INFORMATION

using the SN75112 as a CCITT recommended V.35 line driver

The SN75112 dual line driver, the SN75107A dual line receiver, and some external resistors can be used to

implement the data interchange circuit of CCITT recommendation V.35 (1976) modem specification. The circuit

of one channel is shown in Figure 1 and meets the requirement of the interface as specified by Appendix 11 of

CCITT V.35 and summarized in Table 1 (V.35 has been replaced by ITU V.11).

Table 1. CCITT V.35 Electrical Requirements

MIN

MAX

UNIT

GENERATOR

Source impedance, Zsource

50

150

Ω

Resistance to ground, R

135

165

Ω

Differential output voltage, VOD

440

660

mV

10% to 90% rise time, tr

40

ns

or

0.01

× ui †

Common-mode output voltage, VOC

– 0.6

0.6

V

LOAD (RECEIVER)

Input impedance, ZI

90

110

Ω

Resistance to ground, R

135

165

Ω

† ui = unit interval or minimum signal element pulse width

1Y

Data Out

1G

Enable

Data In

1B

Enable

1C

1A

5 V

5 V

1/2 SN75112

1

2

10

3

13

12

R3

390

Ω

1 Y

1 Z

R1

1.3 k

Ω

R5

75

Ω

R4

390

Ω

5 V

R2

1.3 k

Ω

R6

50

Ω

R7

50

Ω

R8

125

Ω

1A

1B

1

2

5 V

6

Strobe

4

5

1/2 SN75107A

100 pF

100 pF

All resistors are 5%, 1/4 W.

Figure 6. CCITT Recommended V.35 Interface Using the SN75112 and SN75107A