SN54LVC257A, SN74LVC257A

QUADRUPLE 2LINE TO 1LINE DATA SELECTORS/MULTIPLEXERS

WITH 3STATE OUTPUTS

SCAS294N − JANUARY 1993 − REVISED OCTOBER 2003

6

POST OFFICE BOX 655303

PARAMETER MEASUREMENT INFORMATION

VM

th

tsu

From Output

Under Test

CL

(see Note A)

LOAD CIRCUIT

S1

VLOAD

Open

GND

RL

RL

Data Input

Timing Input

VI

0 V

VI

0 V

0 V

tw

Input

VOLTAGE WAVEFORMS

SETUP AND HOLD TIMES

VOLTAGE WAVEFORMS

PROPAGATION DELAY TIMES

INVERTING AND NONINVERTING OUTPUTS

VOLTAGE WAVEFORMS

PULSE DURATION

tPLH

tPHL

tPHL

tPLH

VOH

VOH

VOL

VOL

VI

0 V

Input

Output

Waveform 1

S1 at VLOAD

(see Note B)

Output

Waveform 2

S1 at GND

(see Note B)

VOL

VOH

tPZL

tPZH

tPLZ

tPHZ

VLOAD/2

0 V

VOL + V∆

VOH − V∆

≈0 V

VI

VOLTAGE WAVEFORMS

ENABLE AND DISABLE TIMES

LOW- AND HIGH-LEVEL ENABLING

Output

Output

tPLH/tPHL

tPLZ/tPZL

tPHZ/tPZH

Open

VLOAD

GND

TEST

S1

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

≤ 10 MHz, ZO = 50 Ω.

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

E. tPLZ and tPHZ are the same as tdis.

F. tPZL and tPZH are the same as ten.

G. tPLH and tPHL are the same as tpd.

H. All parameters and waveforms are not applicable to all devices.

Output

Control

VM

VM

VM

VM

VM

VM

VM

VM

VM

VM

VM

VM

VI

VM

VM

1.8 V

± 0.15 V

2.5 V

± 0.2 V

2.7 V

3.3 V

± 0.3 V

1 k

Ω

500

Ω

500

Ω

500

Ω

VCC

RL

2

× VCC

2

× VCC

6 V

6 V

VLOAD

CL

30 pF

30 pF

50 pF

50 pF

0.15 V

0.15 V

0.3 V

0.3 V

V∆

VCC

VCC

2.7 V

2.7 V

VI

VCC/2

VCC/2

1.5 V

1.5 V

VM

tr/tf

≤2 ns

≤2 ns

≤2.5 ns

≤2.5 ns

INPUTS

Figure 1. Load Circuit and Voltage Waveforms