HCPL-063L-060 Avago Technologies US Inc., HCPL-063L-060 Datasheet - Page 19

• Manufacturer Part Number: HCPL-063L-060
• Manufacturer: Avago Technologies US Inc.

Specifications of HCPL-063L-060

• Number Of Elements: 2
• Input Type: DC
• Forward Voltage: 1.75V
• Forward Current: 15mA
• Output Current: 50mA
• Package Type: SOIC
• Operating Temp Range: -40C to 85C
• Power Dissipation: 60mW
• Propagation Delay Time: 90ns
• Pin Count: 8
• Mounting: Surface Mount
• Reverse Breakdown Voltage: 5V
• Operating Temperature Classification: Industrial
• Output Type: Open Collector
• Isolation Voltage: 3750Vrms
• Lead Free Status / RoHS Status: Not Compliant

Figure 13. Recommended drive circuit for High-CMR.
19
Application Information
Common-Mode Rejection for HCPL-260L Families:
Figure 13 shows the recom mended drive circuit for op-
timal common-mode rejection performance. Two main
points to note are:
1. The enable pin is tied to V
2. Two LED-current setting resistors are used instead of
If the enable pin is left floating, it is possible for common-
mode transients to couple to the enable pin, resulting in
common-mode failure. This failure mechanism only oc-
curs when the LED is on and the output is in the Low
State. It is identified as occurring when the transient out-
put voltage rises above 0.8 V. Therefore, the enable pin
should be connected to either V
best common-mode performance with the output low
(CMR
channel parts which have the enable function.
OR ANY TOTEM-POLE
Figure 14. AC equivalent circuit.
OUTPUT LOGIC GATE
1/2 R
1/2 R
applies to single-channel parts only).
one. This is to balance I
mode transients.
L
LED
LED
*
). This failure mechanism is only present in single-
HIGHER CMR MAY BE OBTAINABLE BY CONNECTING PINS 1, 4 TO INPUT GROUND (GND1).
V CC
1
2
3
4
74LS04
I
LN
SHIELD
GND1
+
I
C
LP
V
LC
CM
C
220 Ω
220 Ω
LA
–
LED
CC
variation during common-
rather than floating (this
CC
*
*
1
2
3
4
8
7
6
5
or logic-level high for
SHIELD
HCPL-260L
0.01 μF
15 pF
350 Ω
8
7
6
5
V
V
GND
CC
O
Also, common-mode transients can capacitively cou-
ple from the LED anode (or cathode) to the output-side
ground causing current to be shunted away from the
LED (which can be bad if the LED is on) or conversely
cause current to be injected into the LED (bad if the LED
is meant to be off ). Figure 14 shows the parasitic capaci-
tances which exists between LED anode/cathode and
output ground (C
the input side is an AC-equivalent circuit.
For transients occurring when the LED is on, common-
mode rejec tion (CMR
state) depends upon the amount of LED current drive
(I
threshold (I
I
tion where common-mode transients cause a momen-
tary decrease in I
transients which are fast enough.
+
LP
F
). For conditions where I
and I
0.01 μF
LN
GND2
balance each other. In other words, any condi-
350 Ω
TH
), CMR
V O
GND
V CC+
LA
F
will cause common-mode failure for
and C
L
also depends on the extent which
L
, since the output is in the “low”
LC
). Also shown in Figure 14 on
F
is close to the switching