Application Information
Bypassing and PC Board Layout
The HCPL-x710 optocouplers are
extremely easy to use. No external
interface circuitry is required
because the HCPL-x710 use high-
speed CMOS IC technology
allowing CMOS logic to be
connected directly to the inputs
and outputs.
As shown in Figure 12, the only
external components required for
proper operation are two bypass
capacitors. 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. Figure 13
illustrates the recommended
printed circuit board layout for
the HPCL-x710.
V
DD1
C1
V
I
1
2
NC 3
GND
1
4
8
C2
7 NC
6
5
GND
2
710
YWW
V
DD2
V
O
C1, C2 = 0.01 µF TO 0.1 µF
Figure 12. Recommended Printed Circuit Board layout.
V
DD1
V
I
C1
V
DD2
710
YWW
C2
V
O
GND
1
GND
2
C1, C2 = 0.01 µF TO 0.1 µF
Figure 13. Recommended Printed Circuit Board layout.
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 propaga-
tion delay from low to high (t
PLH
)
is the amount 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
PHL
) is the
amount of time required for the
input signal to propagate to the
output, causing the output to
change from high to low. See
Figure 14.
INPUT
V
I
t
PLH
OUTPUT
V
O
90%
10%
t
PHL
90%
5 V CMOS
50%
0V
10%
V
OH
2.5 V CMOS
V
OL
Figure 14.
9
AGILENT [ AGILENT TECHNOLOGIES, LTD. ]
