ACPL-W70L-020E Avago Technologies US Inc., ACPL-W70L-020E Datasheet - Page 12

• Manufacturer Part Number: ACPL-W70L-020E
• Description: OPTOCOUPLER 2CH 15MBD CMOS 6SSOP
• Manufacturer: Avago Technologies US Inc.

Specifications of ACPL-W70L-020E

• Input Type: DC
• Package / Case: 6-SSOP
• Voltage - Isolation: 5000Vrms
• Number Of Channels: 1, Unidirectional
• Current - Output / Channel: 10mA
• Data Rate: 15MBd
• Propagation Delay High - Low @ If: 23ns @ 6mA
• Current - Dc Forward (if): 10mA
• Output Type: Push-Pull, Totem-Pole
• Mounting Type: Surface Mount
• Maximum Fall Time: 3.5 ns
• Maximum Rise Time: 3.5 ns
• Output Device: Logic Gate Photo IC
• Configuration: 1 Channel
• Maximum Baud Rate: 15 MBps
• Maximum Forward Diode Voltage: 1.85 V
• Maximum Input Diode Current: 6 mA
• Maximum Operating Temperature: + 105 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Common Mode Rejection for ACPL-W70L AND ACPL-K73L
Figure 13 shows the recommended driving circuit for the
ACPL-W70L and ACPL-K73L for optimal common-mode re-
jection performance. Two LED-current setting resistors are
used instead of one. This is to balance the common mode
impedance at LED anode and cathode. Common-mode
transients can capacitively couple 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 ). Figure14 shows the
parasitic capacitances which exists between LED anode/
cathode and output ground (C
Figure 14 on the input side is an AC-equivalent circuit.
Table 1 indicates the directions of I
ing on the direction of the common-mode transient. For
transients occurring when the LED is on, common-mode
rejection (CM
pends upon the amount of LED current drive (I
ditions where I
CM
Figure 13. Recommended drive circuit for ACPL-W70L and ACPL-K73L for high-CMR
12
Figure 14. AC equivalent of ACPL-W70L and ACPL-K73L
74LS04 OR ANY TOTEM-
POLE OUTPUT LOGIC GATE
L
also depends on the extent which I
½ R
½ R
total
total
L
, since the output is in the “low” state) de-
V
F
DD1
SHIELD
is close to the switching threshold (I
I
GND
LN
I
C
1
LP
LC
C
LA
LA
1/2R
1/2R
and C
LP
total
total
and I
R
LC
LP
total
). Also shown in
LN
and I
0.1μF
= 580Ω for V
=300Ω for V
SHIELD
flow depend-
F
LN
). For con-
balance
15pF
DD
DD
V
GND
V
TH
=3.3V
=5V
O
DD2
),
2
each other. In other words, any condition where common-
mode transients cause a momentary decrease in I
when dV
cause common-mode failure for transients which are fast
enough.
Likewise for common-mode transients which occur when
the LED is off (i.e. CM
balance between I
to or greater than the switching threshold of the optocou-
pler, the transient “signal” may cause the output to spike
below 2V (which constitutes a CM
By using the recommended circuit in Figure 13, good CM
can be achieved. The resistors recommended in Figure 13
include both the output impedence of the logic driver cir-
cuit and the external limiting resistor. The balanced I
setting resistors help equalize the common mode voltage
change at anode and cathode to reduce the amount by
which I
C
0.1μF
LA
and C
LED
CM
LC
is modulated from transient coupling through
GND
V
/dt>0 and |I
.
V
DD2
O
2
LP
H
and I
, since the output is “high”), if an im-
FP
| > |I
LN
results in a transient I
FN
|, referring to Table 1) will
H
failure).
F
equal
F
LED
(i.e.
R
-