SN55110A, SN75110A, SN75112

DUAL LINE DRIVERS

SLLS106E – DECEMBER 1975 – REVISED APRIL 2000

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of CCITT V.35 and summarized in Table 1 (V.35 has been replaced by ITU V.11).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

GENERATOR

MIN

MAX

UNIT

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)

MIN

MAX

UNIT

Input impedance, ZI

90

110

Ω

Resistance to ground, R

135

165

Ω

† ui = unit interval or minimum signal-element pulse duration

Data Out

1Y

Data In

1B

Enable

1C

1A

R3

390

Ω

R1

1.3 k

Ω

R5

75

Ω

R4

390

Ω

R2

1.3 k

Ω

R6

50

Ω

R7

50

Ω

R8

100 pF

All resistors are 5%, 1/4 W.

5 V

5 V

5 V

5 V

13

12

1/2 SN75112

1

2

10

3

100 pF

1Y

1Z

1

2

125

Ω

1A

1B

1/2 SN75107A

Enable

1G

4

5

6

Strobe

Figure 5. CCITT-Recommended V.35 Interface Using the SN75112 and SN75107A