SN54HC148, SN74HC148

8LINE TO 3LINE PRIORITY ENCODERS

SCLS109G − MARCH 1984 − REVISED APRIL 2004

6

POST OFFICE BOX 655303

PARAMETER

TEST CONDITIONS

TYP

UNIT

Cpd

Power dissipation capacitance

No load

35

pF

PARAMETER MEASUREMENT INFORMATION

VOLTAGE WAVEFORM

INPUT RISE AND FALL TIMES

50%

50%

10%

10%

90%

90%

VCC

0 V

tr

tf

Input

VOLTAGE WAVEFORMS

PROPAGATION DELAY AND OUTPUT TRANSITION TIMES

50%

50%

50%

10%

10%

90%

90%

VCC

VOH

VOL

0 V

tr

tf

Input

In-Phase

Output

50%

tPLH

tPHL

50%

50%

10%

10%

90%

90%

VOH

VOL

tr

tf

tPHL

tPLH

Out-of-Phase

Output

Test

Point

From Output

Under Test

CL = 50 pF

(see Note A)

LOAD CIRCUIT

NOTES: A. CL includes probe and test-fixture capacitance.

B. Phase relationships between waveforms were chosen arbitrarily. All input pulses are supplied by generators having the following

characteristics: PRR

≤ 1 MHz, ZO = 50 Ω, tr = 6 ns, tf = 6 ns.

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

D. tPLH and tPHL are the same as tpd.

Figure 1. Load Circuit and Voltage Waveforms