Philips Semiconductors
Transceivers
Product specification
74ALS620A/74ALS620A-1
74ALS623A/74ALS623A-1
AC WAVEFORMS
For all waveforms, VM = 1.3V.
An, Bn
VM
tPHL
VM
tPLH
Bn, An
VM
VM
SF00773
Waveform 1. Propagation Delay for Inverting Outputs
An, Bn
VM
tPLH
VM
tPHL
Bn, An
VM
VM
SF00202
Waveform 2. Propagation Delay for Non-inverting Outputs
OEBA
OEAB
VM
tPZH
VM
tPHZ
VOH -0.3V
An or Bn
VM
0V
SF00412
Waveform 3. 3-State Output Enable Time to High Level
and Disable Time from High Level
TEST CIRCUIT AND WAVEFORMS
OEBA
OEAB
VM
tPZL
VM
tPLZ
An or Bn
VM
VOL +0.3V
SF00413
Waveform 4. 3-State Output Enable Time to Low Level
and Disable Time from Low Level
VCC
VIN
VOUT
RL
PULSE
D.U.T.
GENERATOR
7.0V
90%
NEGATIVE
PULSE
tw
VM
10%
tTHL (tff)
VM
10%
tTLH (tr )
90%
AMP (V)
0.3V
RT
CL RL
Test Circuit for 3-State Outputs
SWITCH POSITION
TEST SWITCH
tPLZ, tPZL closed
All other open
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.
POSITIVE
PULSE
10%
tTLH (tr )
90%
VM
tw
tTHL (tf )
90%
VM
AMP (V)
10%
0.3V
Input Pulse Definition
INPUT PULSE REQUIREMENTS
Family
Amplitude VM Rep.Rate tw tTLH
74ALS 3.5V 1.3V 1MHz 500ns 2.0ns
tTHL
2.0ns
SC00072
1991 Feb 08
8