HCPL-5121 Avago Technologies US Inc., HCPL-5121 Datasheet - Page 14

• Manufacturer Part Number: HCPL-5121
• Description: OPTOCOUPLER 2A HERM SEAL 8DIP
• Manufacturer: Avago Technologies US Inc.

Specifications of HCPL-5121

• Output Type: Push-Pull, Totem-Pole
• Package / Case: 8-DIP (0.300", 7.62mm)
• Voltage - Isolation: 1500VDC
• Number Of Channels: 1, Unidirectional
• Current - Output / Channel: 2A
• Propagation Delay High - Low @ If: 300ns @ 10mA ~ 18mA
• Current - Dc Forward (if): 25mA
• Input Type: DC
• Mounting Type: Through Hole
• Configuration: 1 Channel
• Maximum Propagation Delay Time: 500 ns
• Maximum Forward Diode Voltage: 1.8 V
• Minimum Forward Diode Voltage: 1.2 V
• Maximum Reverse Diode Voltage: 5 V
• Maximum Forward Diode Current: 18 mA
• Maximum Power Dissipation: 295 mW
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 55 C
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

CMR with the LED On (CMR
A high CMR LED drive circuit must keep the LED on dur-
ing common mode transients. This is achieved by over-
driving the LED current beyond the input threshold so
that it is not pulled below the threshold during a tran-
sient. A minimum LED current of 0 mA provides ade-
quate margin over the maximum I
0 kV/µs CMR.
Figure 30. Equivalent Circuit for Figure 25 During Common Mode Transient.
Figure 31. Not Recommended Open Collector Drive Circuit
4
+5 V
+5 V
Q1
V
+
_
SAT
1
2
3
4
* THE ARROWS INDICATE THE DIRECTION
OF CURRENT FLOW DURING ∆dV CM /dt
1
2
3
4
C
C
I
LEDN
LEDP
LEDN
C
C
SHIELD
I
LEDP
LEDN
LEDP
SHIELD
V CM
+
H
).
_
FLH
of  mA to achieve
8
7
6
5
8
7
6
5
0.1
µF
+
_
Rg
V CC = 18 V
CMR with the LED Off (CMR
A high CMR LED drive circuit must keep the LED off (V
≤ V
during a -dV
ing through C
the logic gate. As long as the low state voltage devel-
oped across the logic gate is less than V
remain off and no common mode failure will occur.
The open collector drive circuit, shown in Figure 3, can-
not keep the LED off during a +dV
all the current flowing through C
by the LED, and it is not recommended for applications
requiring ultra high CMR
alternative drive circuit which, like the recommended
application circuit (Figure 25), does achieve ultra high
CMR performance by shunting the LED in the off state.
Figure 32. Recommended LED Drive Circuit for Ultra-High CMR
* * *
* * *
+5 V
F(OFF)
) during common mode transients. For example,
1
2
3
4
cm
/dt transient in Figure 30, the current flow-
LEDP
C
C
LEDP
LEDN
also flows through the R
SHIELD
L
L
).
performance. Figure 32 is an
LEDN
cm
8
7
6
5
/dt transient, since
must be supplied
F(OFF)
SAT
, the LED will
and V
SAT
of
F