SN75976A, SN55976A

9-CHANNEL DIFFERENTIAL TRANSCEIVER

SLLS218B – MAY 1995 – REVISED MAY 1997

11

POST OFFICE BOX 655303

PARAMETER MEASUREMENT INFORMATION

IO

IO

VOD

VO

VO

B+

B–

A

II

15 pF

15 pF

75

Ω

165

Ω

375

Ω

375

Ω

S1

S2

165

Ω

SN75976A = 5 V

SN55976A = 4.5 V

AB

VI

Input

(see Note A)

†

† CDE0 and DE/RE are at 2 V, BSR is at 0.8 V and, for the SN75976A only, all others are open.

‡ For the SN75976A only, all nine drivers are enabled, similarly loaded, and switching.

1.5 V

1.5 V

90%

90%

10%

10%

0V

0V

tPLH

tPHL

3 V

0 V

VOD(H)

VOD(L)

S1 to A or B

Input

Output, VOD

tr

tf

Figure 2. Driver Delay and Transition Time Test Waveforms

Generator

(see Note A)

Generator

(see Note A)

50

Ω

50

Ω

VID

Input B –

IO

VO

† CDE0, CDE1, CDE2, BSR, CRE, and DE/RE at 0.8 V

CL = 15 pF

Output

Input B +

†

‡ For the SN75976A only, all nine receivers are enabled and switching.

NOTES: A. All input pulses are supplied by a generator having the following characteristics: tr ≤ 6 ns, tf ≤ 6 ns, PRR ≤ 1 MHz, duty cycle = 50%,

ZO = 50 Ω.

B. All resistances are in

Ω and ± 5%, unless otherwise indicated.

C. All capacitances are in pF and

± 10%, unless otherwise indicated.

D. All indicated voltages are

± 10 mV.