acpl-w70l Avago Technologies, acpl-w70l Datasheet - Page 9

• Manufacturer Part Number: acpl-w70l
• Description: Single-channel And Dual-channel High Speed 15 Mbd Cmos Optocoupler With Glitch-free Power-up Feature
• Manufacturer: Avago Technologies

Figure 7. Typical V
Application Information
Bypassing and PC Board Layout
The ACPL-W70L and ACPL-K73L optocouplers are ex-
tremely easy to use. ACPL-W70L and ACPL-K73L provide
CMOS logic output due to the high-speed CMOS IC tech-
nology used.
The external components required for proper operation
are the input limiting resistor and the output bypass ca-
pacitor. Capacitor values should be between 0.01 µF and
0.1 µF.
For each capacitor, the total lead length between both
ends of the capacitor and the power-supply pins should
not exceed 20 mm.
Propagation Delay, Pulse-Width Distortion and Propagation Delay
Skew
Propagation delay is a figure of merit which describes how
quickly a logic signal propagates through a system. The
propagation delay from low to high (t
of time required for an input signal to propagate to the
output, causing the output to change from low to high.
Similarly, the propagation delay from high to low (t
the amount of time required for the input signal to propa-
gate to the output, causing the output to change from
high to low (see Figure 9).
9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1
-40
F
-20
vs. temperature.
0
T
A
-TEMPERATURE- o C
20
40
PLH
60
) is the amount
80
PHL
100
) is
Pulse-width distortion (PWD) results when t
differ in value. PWD is defined as the difference between
t
between t
mum data rate capability of a transmission system. PWD
can be expressed in percent by dividing the PWD (in ns)
by the minimum pulse width (in ns) being transmitted.
Typically, PWD on the order of 20-30% of the minimum
pulse width is tolerable; the exact figure depends on the
particular application (RS232, RS422, T-1, etc.).
Propagation delay skew, t
to consider in parallel data applications where synchroni-
zation of signals on parallel data lines is a concern.
If the parallel data is being sent through a group of opto-
couplers, differences in propagation delays will cause the
data to arrive at the outputs of the optocouplers at differ-
ent times. If this difference in propagation delays is large
enough, it will determine the maximum rate at which par-
allel data can be sent through the optocouplers.
Propagation delay skew is defined as the difference be-
tween the minimum and maximum propagation delays,
either t
which are operating under the same conditions (i.e., the
same supply voltage, output load, and operating temper-
ature). As illustrated in Figure 10, if the inputs of a group of
optocouplers are switched either ON or OFF at the same
PLH
and t
PLH
PHL
PLH
or t
and often PWD is defined as the difference
and t
PHL
, for any given group of optocouplers
PHL
and often determines the maxi-
PSK
, is an important parameter
PLH
and t
PHL