SN74S225

16

× 5 ASYNCHRONOUS FIRST-IN, FIRST-OUT MEMORY

WITH 3-STATE OUTPUTS

SDLS207B – SEPTEMBER 1976 – REVISED APRIL 1998

7

POST OFFICE BOX 655303

PARAMETER MEASUREMENT INFORMATION

tPHZ

tPLZ

0.3 V

tPZL

tPZH

LOAD CIRCUIT FOR 3-STATE OUTPUTS

From Output

Under Test

Test Point

R1 = 500

Ω

S1

CL

(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

SET UP 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

1.3 V

1.3 V

1.3 V

1.3 V

3.5 V

0.3 V

Output

Control

Waveform 1

S1 Closed

(see Note B)

Waveform 2

S1 Open

(see Note B)

0 V

VOH

VOL

3.5 V

0.3 V

1.3 V

1.3 V

VOLTAGE WAVEFORMS

ENABLE AND DISABLE TIMES, 3-STATE OUTPUTS

R2 = 500

Ω

tw

tPZH

tPZL

tPHZ

tPLZ

tPLH

tPHL

Open

Closed

Open

Closed

Open

Open

PARAMETER

S1

ten

tdis

tpd

tPHL

tPLH

tPLH

tPHL

Input

(see Note C)

Out-of-Phase

Output

1.3 V

1.3 V

1.3 V

1.3 V

1.3 V

1.3 V

3.5 V

0.3 V

VOL

VOH

VOH

VOL

In-Phase

Output

VOLTAGE WAVEFORMS

PROPAGATION DELAY TIMES

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 ns, tf ≤ 2 ns.

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

Figure 1. Load Circuit and Voltage Waveforms