HCPL-5151-200 データシートの表示（PDF） - Broadcom Corporation
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HCPL-5151-200 Datasheet PDF : 18 Pages
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HCPL-5150 and HCPL-5151,
DLA SMD 5962-04205
Figure 27 Energy Dissipated in the HCPL-515x for Each IGBT
Switching Cycle
7
Qg = 100 nC
6
Qg = 250 nC
Qg = 500 nC
5
4
VCC = 19 V
VEE = -9 V
3
2
1
0
0
20
40
60
80
100
Rg - GATE RESISTANCE - :
Figure 28 Optocoupler Input to Output Capacitance Model for
Unshielded Optocouplers
1
8
CLEDP
2
7
3
6
CLEDN
4
5
Figure 29 Optocoupler Input to Output Capacitance Model for
Shielded Optocouplers
1
CLEDO1
8
CLEDP
2
7
CLEDO2
3
CLEDN
6
4
5
SHIELD
Data Sheet
CMR with the LED On (CMRH)
A high CMR LED drive circuit must keep the LED on during
common mode transients. This is achieved by overdriving the
LED current beyond the input threshold so that it is not pulled
below the threshold during a transient. A minimum LED
current of 10 mA provides adequate margin over the maximum
IFLH of 7 mA to achieve 10 kV/μs CMR.
CMR with the LED Off (CMRL)
A high CMR LED drive circuit must keep the LED off (VF ≤
VF(OFF)) during common mode transients. For example, during
a –dVCM/dt transient in Figure 30, the current flowing through
CLEDP also flows through the RSAT and VSAT of the logic gate. As
long as the low state voltage developed across the logic gate is
less than VF(OFF), the LED remains off and no common mode
failure occurs.
Figure 30 Equivalent Circuit for Figure 25 During Common Mode
Transient
+5 V
+
V_SAT
1
CLEDP
2
ILEDP
3
CLEDN
4
SHIELD
8
0.1
μF
7
+
_
V CC = 18 V
6
***
Rg
5
***
* THE ARROWS INDICATE THE DIRECTION
OF CURRENT FLOW DURING -dVCM/dt
+_
V CM
The open collector drive circuit, shown in Figure 31, cannot
keep the LED off during a +dVCM/dt transient, since all the
current flowing through CLEDN must be supplied by the LED,
and it is not recommended for applications requiring ultra high
CMRL performance. Figure 32 is an 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.
Broadcom
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