Input

1.5 V

1.5 V

3 V

0 V

tPLH

tPLH

tPHL

tPHL

In-Phase

Output

Out-of-Phase

Output

VOH

VOL

VOH

VOL

50% VCC

50% VCC

50% VCC

50% VCC

A.

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

Figure 6-4. Voltage Waveforms Propagation Delay Times Inverting and Noninverting Outputs

1.5 V

th

1.5 V

1.5 V

0 V

3 V

0 V

3 V

Timing Input

Data Input

1.5 V

tSU

Figure 6-5. Voltage Waveforms Setup And Hold Times

1.5 V

50% VCC

3 V

0 V

§ 9CC

§ 0 V

VOH

VOL

tPLZ

tPHZ

tPZL

tPZH

Output

Control

Output

Waveform 1

(1)

S1 at VCC

Output

Waveform 2

(2)

S1 at GND

1.5 V

VOH ± 0.3 V

50% VCC

VOL + 0.3 V

A.

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

B.

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

C.

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

Figure 6-6. Voltage Waveforms Enable And Disable Times Low- and High-Level Enabling

SN54AHCT240, SN74AHCT240

SCLS252P – OCTOBER 1995 – REVISED JANUARY 2025

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