Philips Semiconductors
1-of-8 decoder (3-State)
Product specification
74F538
TEST CIRCUIT AND WAVEFORM
VCC
VIN
PULSE
GENERATOR
VOUT
RL
D.U.T.
RT
CL RL
Test Circuit for 3-State Outputs
SWITCH POSITION
TEST
tPLZ
tPZL
All other
SWITCH
closed
closed
open
7.0V
90%
NEGATIVE
PULSE
POSITIVE
PULSE
10%
tw
VM
10%
tTHL (tf )
VM
10%
tTLH (tr )
tTLH (tr )
90%
VM
tw
tTHL (tf )
90%
VM
Input Pulse Definition
90%
AMP (V)
0V
AMP (V)
10%
0V
DEFINITIONS:
RL = Load resistor;
see AC electrical characteristics for value.
CL = Load capacitance includes jig and probe capacitance;
see AC electrical characteristics for value.
RT = Termination resistance should be equal to ZOUT of
pulse generators.
INPUT PULSE REQUIREMENTS
family
amplitude VM rep. rate
tw
tTLH
74F
3.0V 1.5V 1MHz 500ns 2.5ns
tTHL
2.5ns
SF00777
1989 Apr 06
6