HCPL-316J-500E Datasheet, PDF (29/33 Pages) AVAGO TECHNOLOGIES LIMITED – 2.5 Amp Gate Drive Optocoupler with Integrated (VCE) Desaturation Detection and Fault Status Feedback

Higher Output Current Using an External Current Buf-
fer:
To increase the IGBT gate drive current, a non-inverting
current buffer (such as the npn/pnp buffer shown in
Figure 75) may be used. Inverting types are not com-
patible with the desatura-tion fault protection circuitry
and should be avoided. To preserve the slow IGBT turn-
off feature during a fault condition, a 10 nF capacitor
should be connected from the buffer input to V_EE and
a 10 : resistor inserted between the output and the
common npn/pnp base. The MJD44H11/MJD45H11
pair is appropriate for currents up to 8A maximum. The
D44VH10/ D45VH10 pair is appropriate for currents up
to 15 A maximum.
HCPL-316J
V_E 16
V_LED2+ 15
DESAT 14
100 pF
V_CC2 13
V_C 12
V_OUT 11
V_EE 10
V_EE 9
10 Ω
10 nF
15 V
MJD44H11 or
D44VH10
4.5 Ω
2.5 Ω
MJD45H11 or
D45VH10
-5 V
DESAT Diode and DESAT Threshold
The DESAT diode’s function is to conduct forward cur-
rent, allowing sensing of the IGBT’s saturated collector-
to-emitter voltage, V_CESAT, (when the IGBT is “on”) and to
block high voltages (when the IGBT is “off”). During the
short period of time when the IGBT is switching, there is
commonly a very high dV_CE/dt voltage ramp rate across
the IGBT’s collector-to-emitter. This results in I_CHARGE (=
C_D-DESAT x dV_CE/dt) charging current which will charge
the blanking capacitor, C_BLANK. In order to minimize
this charging current and avoid false DESAT triggering,
it is best to use fast response diodes. Listed in the be-
low table are fast-recovery diodes that are suitable for
use as a DESAT diode (D_DESAT). In the recommended ap-
plication circuit shown in Figure 62, the voltage on pin
14 (DESAT) is V_DESAT = V_F + V_CE, (where V_F is the forward
ON voltage of D_DESAT and V_CE is the IGBT collector-to-
emitter voltage). The value of V_CE which triggers DESAT
to signal a FAULT condition, is nominally 7V – V_F. If de-
sired, this DESAT threshold voltage can be decreased by
using multiple DESAT diodes in series. If n is the number
of DESAT diodes then the nominal threshold value be-
comes V_CE,FAULT(TH) = 7 V – n x V_F. In the case of using two
diodes instead of one, diodes with half of the total re-
quired maximum reverse-voltage rating may be chosen.
Figure 75. Current buffer for increased drive current.
Part Number
MUR1100E
MURS160T3
UF4007
BYM26E
BYV26E
BYV99
Manufacturer
Motorola
Motorola
General Semi.
Philips
Philips
Philips
t_rr (ns)
75
75
75
75
75
75
Max. Reverse Voltage
Rating, V_RRM (Volts)
1000
600
1000
1000
1000
600
Package Type
59-04 (axial leaded)
Case 403A (surface mount)
DO-204AL (axial leaded)
SOD64 (axial leaded)
SOD57 (axial leaded)
SOD87 (surface mount)
Power/Layout Considerations
Operating Within the Maximum Allowable Power Ratings
(Adjusting Value of R_G):
When choosing the value of R_G, it is important to con-
firm that the power dissipation of the HCPL-316J is
within the maximum allowable power rating.
The steps for doing this are:
1. Calculate the minimum desired R_G;
2. Calculate total power dissipation in the part referring
to Figure 77. (Average switching energy supplied to
HCPL-316J per cycle vs. R_G plot);
3. Compare the input and output power dissipation
calculated in step #2 to the maximum recommended
dissipation for the HCPL-316J. (If the maximum rec-
ommended level has been exceeded, it may be nec-
essary to raise the value of R_G to lower the switching
power and repeat step #2.)
29