HCPL3150 HP [Agilent(Hewlett-Packard)], HCPL3150 Datasheet - Page 10

• Manufacturer Part Number: HCPL3150
• Description: 0.5 Amp Output Current IGBT Gate Drive Optocoupler
• Manufacturer: HP [Agilent(Hewlett-Packard)]

Figure 24. CMR Test Circuit and Waveforms.
Figure 25. Recommended LED Drive and Application Circuit.
1-206
Figure 23. t
Applications Information
Eliminating Negative IGBT
Gate Drive
To keep the IGBT firmly off, the
HCPL-3150 has a very low
maximum V
1.0 V. The HCPL-3150 realizes
this very low V
DMOS transistor with 4
(typical) on resistance in its pull
down circuit. When the
HCPL-3150 is in the low state,
50% DUTY
5 V
CONTROL
CYCLE
10 KHz
COLLECTOR
INPUT
+
–
I
F
+5 V
= 7 to 16 mA
74XXX
I
+
–
OPEN
F
500
PLH
A
B
OL
270
, t
specification of
OL
PHL
1
2
3
4
1
2
3
4
by using a
, t
r
, and t
V
1
2
3
4
CM
f
+
= 1500 V
Test Circuit and Waveforms.
HCPL-3150
the IGBT gate is shorted to the
emitter by Rg + 4 . Minimizing
Rg and the lead inductance from
the HCPL-3150 to the IGBT gate
and emitter (possibly by
mounting the HCPL-3150 on a
small PC board directly above the
IGBT) can eliminate the need for
negative IGBT gate drive in many
applications as shown in Figure
25. Care should be taken with
such a PC board design to avoid
8
7
6
5
8
7
6
5
8
7
6
5
0.1 µF
0.1 µF
0.1 µF
47
V
3 nF
O
V
O
+
–
+
–
V
V
CC
+
–
to 30 V
CC
V
= 30 V
CC
= 15
Rg
= 18 V
V
0 V
V
SWITCH AT A: I
V
SWITCH AT B: I
Q1
Q2
CM
O
O
I
V
F
OUT
t
routing the IGBT collector or
emitter traces close to the HCPL-
3150 input as this can result in
unwanted coupling of transient
signals into the HCPL-3150 and
degrade performance. (If the
IGBT drain must be routed near
the HCPL-3150 input, then the
LED should be reverse-biased
when in the off state, to prevent
the transient signals coupled
from the IGBT drain from turning
on the HCPL-3150.)
PLH
F
F
t
t
= 10 mA
= 0 mA
r
3-PHASE
+ HVDC
- HVDC
AC
t
PHL
t
f
90%
50%
10%
V
t
=
V
CM
t
V
V
OH
OL