HD74HC640, HD74HC643

Rev.2.00 Mar 30, 2006 page 7 of 10

Waveforms

HD74HC640

0 V

10 %

90 %

50 %

50 %

50 %

50 %

50 %

50 %

10 %

90 %

Input A

Output B

0 V

10 %

10 %

90 %

90 %

50 %

50 %

Input

G

Waveform - A

Waveform - B

90 %

10 %

10 %

90 %

10 %

90 %

Notes : 1. Input waveform : PRR

2. Waveform - A is for an output with internal conditions such that the

output is low except when disabled by the output control.

3. Waveform - B is for an output with internal conditions such that the

output is high except when disabled by the output control.

4. The output are measured one at a time with one transition per measurement.