HD74LS243

Rev.3.00, Jul.15.2005, page 4 of 6

Testing Method

Test Circuit

4.5 V

Input

Output

P.G.

Zout = 50

Ω

1B

GBA

GAB

1A

Notes:

1.

2A-2B, 3A-3B, 4A-4B are identical to abobe load circuit.

2.

3.

4.

All diodes are 1S2074(H).

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%