HCPL3120000E AVAGO TECH, HCPL3120000E Datasheet - Page 19

• Manufacturer Part Number: HCPL3120000E
• Manufacturer: AVAGO TECH

Step 2: Check the HCPL-3120
Power Dissipation and Increase Rg
if Necessary. The HCPL-3120 total
power dissipation (P
sum of the emitter power (P
output power (P
P
P
P
For the circuit in Figure 26 with I
(worst case) = 16 mA, Rg = 8 , Max
Duty Cycle = 80%, Qg = 500 nC,
f = 20 kHz and T
P
P
Figure 27. Energy Dissipated in the
HCPL-3120 for Each IGBT Switching
Cycle.
E
O
E
O
T
Parameter
Duty Cycle
= P
14
12
10
= I
= 16 mA 1.8 V 0.8 = 23 mW
= P
= 4.25 mA 20 V
= I
= 85 mW + 104 mW
= 189 mW
8
6
4
2
0
0
P
V
I
F
CC
E
O(BIAS)
F
F
E
Rg – GATE RESISTANCE –
V
+ P
+ E
+ 5.2 J 20 kHz
> 178 mW (P
= 250 mW 15C*4.8 mW/C)
F
(V
10
CC
Duty Cycle
O
SW
+ P
- V
20
(R
O
LED On Voltage
Maximum LED
EE
A
):
Description
LED Current
O (SWITCHING)
G
max = 85C:
Duty Cycle
)
, Q
V
V
T
30
Qg = 100 nC
Qg = 500 nC
Qg = 1000 nC
CC
EE
) is equal to the
G
) f
O(MAX)
= -9 V
= 19 V
40
E
) and the
@ 85C
50
F
P
The value of 4.25 mA for I
previous equation was obtained by
derating the I
(which occurs at -40 C) to I
at 85C (see Figure 7).
Since P
than P
to reduce the HCPL-3120 power
dissipation.
P
For Qg = 500 nC, from Figure 27,
a value of E
Rg = 10.3
O
E
O(SWITCHING MAX)
SW
E
Parameter
= P
= 178 mW - 85 mW
= 93 mW
SW(MAX)
(Rg,Qg)
V
V
I
CC
CC
EE
f
O(MAX)
O(MAX)
O
for this case is greater
SW
, Rg must be increased
= –––––––––––––––
= ––––––– = 4.65 W
.
CC
- P
= 4.65 W gives a
93 mW
20 kHz
P
max of 5 mA
O(BIAS)
O(SWITCHINGMAX)
Energy Dissipated in the HCPL-3120 for each
IGBT Switching Cycle (See Figure 27)
f
CC
CC
in the
Negative Supply Voltage
Positive Supply Voltage
max
Switching Frequency
19
Supply Current
Description