SN75276

FAIL-SAFE DIFFERENTIAL BUS TRANSCEIVER

SLLS212B – SEPTEMBER 1995 – REVISED APRIL 1998

5

POST OFFICE BOX 655303

DRIVER SECTION

electrical characteristics over recommended ranges of supply voltage and operating free-air

temperature (unless otherwise noted)

PARAMETER

TEST CONDITIONS†

MIN

TYP‡

MAX

UNIT

VIK

Input clamp voltage

II = – 18 mA

– 1.5

V

VO

Output voltage

IO = 0

0

6

V

|VOD1|

Differential output voltage

IO = 0

1.5

3.6

6

V

|VOD2|

Differential output voltage

RL = 100 Ω,

See Figure 1

1/2 VOD1or 2§

V

|VOD2|

Differential output voltage

RL = 54 Ω,

See Figure 1

1.5

2.5

5

V

VOD3

Differential output voltage

See Note 3

1.5

5

V

∆|VOD|

Change in magnitude of differential output

±02

V

∆|VOD|

gg

voltage¶

±0.2

V

VOC

Common mode output voltage

RL =54 Ω or 100 Ω

See Figure 1

+3

V

VOC

Common-mode output voltage

RL = 54 Ω or 100 Ω,

See Figure 1

–1

V

∆|VOC|

Change in magnitude of common-mode

±02

V

∆|VOC|

gg

output voltage¶

±0.2

V

IO

Output current

Output disabled,

VO = 12 V

1

mA

IO

Output current

,

See Note 4

VO = – 7 V

– 0.8

mA

IIH

High-level input current

VI = 2.4 V

20

µA

IIL

Low-level input current

VI = 0.4 V

– 400

µA

VO = – 7 V

– 250

IOS

Short circuit output current

VO = 0

150

mA

IOS

Short-circuit output current

VO = VCC

250

mA

VO = 12 V

250

ICC

Supply current (total package)

No load

Outputs enabled

42

70

mA

ICC

Supply current (total package)

No load

Outputs disabled

26

35

mA

† The power-off measurement in ANSI Standard TIA/EIA-422-B applies to disabled outputs only and is not applied to combined inputs and outputs.

‡ All typical values are at VCC = 5 V and TA = 25°C.

§ The minimum VOD2 with a 100-Ω load is either 1/2 VOD1 or 2 V, whichever is greater.

¶

∆|VOD| and ∆|VOC| are the changes in magnitude of VOD and VOC, respectively, that occur when the input is changed from a high level to a low

level.

NOTES:

3. This applies for both power on and off; refer to TIA/EIA-485-A for exact conditions. The TIA/EIA-422-B limit does not apply for a

combined driver and receiver terminal.

4. See TIA/EIA-485-A Figure 3.5, Test Termination Measurement 2.

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

td(OD) Differential-output delay time

RL =54 Ω

See Figure 3

15

22

ns

tt(OD)

Differential-output transition time

RL = 54 Ω,

See Figure 3

20

30

ns

tPZH

Output enable time to high level

See Figure 4

85

120

ns

tPZL

Output enable time to low level

See Figure 5

40

60

ns

tPHZ

Output disable time from high level

See Figure 4

150

250

ns

tPLZ

Output disable time from low level

See Figure 5

20

30

ns