Datasheet

A–3
Output Derating Curves
Propagation-delay, enable-time, and disable-time parameter values in the ALVC data sheets are provided with V
CC
ranging from 3 V to 3.6 V and with a load capacitance of 50 pF. As the load capacitance varies, values for these
parameters change. Data for Figures 1 through 3 were taken under worst-case scenarios, i.e., with V
CC
at 3 V and
T
A
= 85°C. The data are for capacitive loads from 10 pF to 50 pF, in 10-pF increments. Although the data were taken
on the ALVCH16245, the results can be considered representative of all ALVC devices.
Figure A–1 illustrates the effect on propagation delay for high-to-low and low-to-high transitions for the A-to-B
direction; B-to-A results were slightly faster than the A-to-B results, but for clarity are not illustrated. For propagation
delay, a 10-pF decrease in load capacitance produces approximately a 12.5% decrease in propagation delay.
1
1.5
2.0
2.5
3.0
3.5
10 20 30 40 50
PROPAGATION DELAY
vs
LOAD CAPACITANCE
t – Propagation Delay – ns
pd
C
L
– Load Capacitance – pF
A to B t
PLH
A to B t
PHL
Figure A–1