SN74ALS234

64 × 4 ASYNCHRONOUS FIRST IN, FIRST OUT MEMORY

SDAS106B − OCTOBER 1986 − REVISED SEPTEMBER 1993

9

POST OFFICE BOX 655303

POST OFFICE BOX 1443

PARAMETER MEASUREMENT INFORMATION

tPHZ

tPLZ

tPHL

tPLH

0.3 V

tPZL

tPZH

TEST

S1

Open

Open

Open

tPHL

tPZH

tPZL

Closed

Open

Closed

tPHZ

tPLZ

tPLH

tPHL

LOAD CIRCUIT FOR 3-STATE OUTPUTS

From Output

Under Test

Test Point

R1 = 500

Ω

S1

CL = 50 pF

(see Note A)

7 V

Open

1.3 V

1.3 V

1.3 V

3.5 V

3.5 V

0.3 V

0.3 V

th

tsu

VOLTAGE WAVEFORMS

SETUP AND HOLD TIMES

Timing

Input

Data

Input

1.3 V

1.3 V

3.5 V

3.5 V

0.3 V

0.3 V

High-Level

Pulse

Low-Level

Pulse

VOLTAGE WAVEFORMS

PULSE DURATION

Input

(see Note B)

Out-of-Phase

Output

1.3 V

1.3 V

1.3 V

1.3 V

1.3 V

1.3 V

1.3 V

1.3 V

1.3 V

1.3 V

3.5 V

3.5 V

0.3 V

0.3 V

VOL

VOH

VOH

VOL

Output

Control

Waveform 1

S1 Closed

(see Note C)

Waveform 2

S1 Open

(see Note C)

0 V

VOH

VOL

3.5 V

In-Phase

Output

0.3 V

tPLH

1.3 V

1.3 V

VOLTAGE WAVEFORMS

PROPAGATION DELAY TIMES

VOLTAGE WAVEFORMS

ENABLE AND DISABLE TIMES, 3-STATE OUTPUTS

SWITCH POSITION TABLE

R2 = 500

Ω

tw

NOTES: A. CL includes probe and jig capacitance.

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

≤ 1 MHz, Zo = 50 Ω, tr ≤ 2 ns, tf ≤ 2 ns.

C. 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.

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

Figure 5. Load Circuit and Voltage Waveforms