SN54ACT374, SN74ACT374

OCTAL D-TYPE EDGE-TRIGGERED FLIP-FLOPS

WITH 3-STATE OUTPUTS

SCAS539F – OCTOBER 1995 – REVISED NOVEMBER 2002

5

POST OFFICE BOX 655303

PARAMETER MEASUREMENT INFORMATION

50% VCC

3 V

3 V

0 V

0 V

th

tsu

VOLTAGE WAVEFORMS

Data Input

tPLH

tPHL

VOH

VOL

3 V

0 V

Input

Output

Timing Input

50% VCC

From Output

Under Test

CL = 50 pF

(see Note A)

LOAD CIRCUIT

S1

2

× VCC

500

Ω

500

Ω

Output

Control

(low-level

enabling)

Output

Waveform 1

S1 at 2

× VCC

(see Note B)

Output

Waveform 2

S1 at Open

(see Note B)

VOL

VOH

tPZL

tPZH

tPLZ

tPHZ

≈VCC

0 V

50% VCC

VOL + 0.3 V

50% VCC

≈0 V

Open

VOLTAGE WAVEFORMS

tPLH/tPHL

tPLZ/tPZL

tPHZ/tPZH

Open

2

× VCC

Open

TEST

S1

3 V

0 V

tw

VOLTAGE WAVEFORMS

Input

VOH – 0.3 V

3 V

NOTES: A. CL includes probe and jig capacitance.

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. All input pulses are supplied by generators having the following characteristics: PRR

≤ 1 MHz, ZO = 50 Ω, tr ≤ 2.5 ns, tf ≤ 2.5 ns.

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

VOLTAGE WAVEFORMS

1.5 V

1.5 V

1.5 V

1.5 V

1.5 V

1.5 V

1.5 V

1.5 V

1.5 V

Figure 1. Load Circuit and Voltage Waveforms