SN54ACT245, SN74ACT245

OCTAL BUS TRANSCEIVERS

WITH 3-STATE OUTPUTS

SCAS452E – SEPTEMBER 1994 – REVISED OCTOBER 2002

4

POST OFFICE BOX 655303

switching characteristics over recommended operating free-air temperature range,

PARAMETER

FROM

TO

TA = 25°C

SN54ACT245

SN74ACT245

UNIT

PARAMETER

(INPUT)

(OUTPUT)

MIN

TYP

MAX

MIN

MAX

MIN

MAX

UNIT

tPLH

AorB

BorA

1

4

7.5

1

9

1.5

8

ns

tPHL

A or B

B or A

1

4

8

1

10

1

9

ns

tPZH

OE

AorB

1

5

10

1

12

1.5

11

ns

tPZL

OE

A or B

1

5.5

10

1

13

1.5

12

ns

tPHZ

OE

AorB

1

5.5

10

1

12

1

11

ns

tPLZ

OE

A or B

1

5

10

1

12

1.5

11

ns

PARAMETER

TEST CONDITIONS

TYP

UNIT

Cpd

Power dissipation capacitance

CL = 50 pF,

f = 1 MHz

45

pF

PARAMETER MEASUREMENT INFORMATION

LOAD CIRCUIT

tPLH

tPHL

3 V

0 V

50% VCC

50% VCC

VOH

VOL

Input

Output

VOLTAGE WAVEFORMS

From Output

Under Test

CL = 50 pF

(see Note A)

S1

2

× VCC

500

Ω

500

Ω

Open

tPLH/tPHL

tPLZ/tPZL

tPHZ/tPZH

Open

2

× VCC

Open

TEST

S1

Output

Control

(low-level

enabling)

Output

Waveform 1

S1 at 2

× VCC

(see Note B)

Output

Waveform 2

S1 at Open

(see Note B)

VOL

VOH

tPZL

tPZH

tPLZ

tPHZ

≈VCC

0 V

50% VCC

VOL + 0.3 V

50% VCC

≈0 V

VOLTAGE WAVEFORMS

VOH – 0.3 V

3 V

1.5 V

1.5 V

1.5 V

1.5 V

NOTES: A. CL includes probe and jig capacitance.

B. Waveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.

Waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control.

C. All input pulses are supplied by generators having the following characteristics: PRR

≤ 1 MHz, ZO = 50 Ω, tr ≤ 2.5 ns, tf ≤ 2.5 ns.

D. The outputs are measured one at a time with one input transition per measurement.

Figure 1. Load Circuit and Voltage Waveforms