VOLTAGE WAVEFORM

INPUT RISE AND FALL TIMES

50%

50%

10%

10%

90%

90%

0 V

t

Input

f

VOLTAGE WAVEFORMS

PROPAGATION DELAY AND OUTPUT TRANSITION TIMES

50%

50%

50%

10%

10%

90%

90%

0 V

t

Input

f

In-Phase

Output

50%

50%

50%

10%

10%

90%

90%

t

t

r

f

Out-of-Phase

Output

50%

10%

90%

0 V

Output

Control

(Low-Level

Enabling)

Output

Waveform 1

(See Note B)

50%

VOLTAGE WAVEFORMS

ENABLE AND DISABLE TIMES FOR 3-STATE OUTPUTS

≈0 V

50%

50%

Output

Waveform 2

(See Note B)

Test

Point

From Output

Under Test

(see Note A)

S1

S2

LOAD CIRCUIT

PARAMETER

1 k

Ω

1 k

Ω

50 pF

or

150 pF

50 pF

Open

Closed

R

S1

L

Closed

Open

S2

Open

Closed

Closed

Open

50 pF

or

150 pF

Open

Open

−−

SN54HC245, SN74HC245

www.ti.com

SCLS131E – DECEMBER 1982 – REVISED SEPTEMBER 2015

7 Parameter Measurement Information

A.

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.

Phase relationships between waveforms were chosen arbitrarily. All input pulses are supplied by generators having

the following characteristics: PRR

D.

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

E.

F.

G.

Figure 3. Load Circuit and Voltage Waveforms

Copyright © 1982–2015, Texas Instruments Incorporated

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