HD74LS642

Rev.2.00, Feb.18.2005, page 4 of 6

Testing Method

Test Circuit

1A

1B

DIR

G

Input

P.G.

Ω

4.5V

Output

Notes:

1.

2A-2B, 3A-3B, 4A-4B, 5A-5B, 6A-6B, 7A-7B, 8A-8B, are identical to abobe load circuit.

2.

3.

Waveforms 1

Input A

(or B)

Output B

(or A)

3 V

0 V

1.3 V

1.3 V

1.3 V

1.3 V

10 %

10 %

90 %

90 %

Note:

≤ 15 ns, t

THL

≤ 6 ns, PRR = 1 MHz, duty cycle 50%