HCPL-316J 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 Buffer:
To increase the IGBT gate drive current, a non-invert-
ing current buffer (such as the npn/pnp buffer shown in
Figure 75) may be used. Inverting types are not compat-
ible with the desatura-tion fault protection circuitry and
should be avoided.To preserve the slow IGBT turn-off fea-
ture during a fault condition, a 10 nF capacitor should be
connected from the buffer input to V_EE and a 10 W resis-
tor 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 below
table are fast-recovery diodes that are suitable for use
as a DESAT diode (D_DESAT). In the recommended appli-
cation 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-emit-
ter voltage). The value of V_CE which triggers DESAT to
signal a FAULT condition, is nominally 7V – V_F. If desired,
this DESAT threshold voltage can be decreased by using
multiple DESAT diodes in series. If n is the number of DE-
SAT diodes then the nominal threshold value becomes
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 required
maximum reverse-voltage rating may be chosen.
Figure 75. Current buffer for increased drive current.

Part Number
Manufacturer
t_rr (ns)
MUR1100E
Motorola
75
MURS160T3
Motorola
75
UF4007
General Semi.
75
BYM26E
Philips
75
BYV26E
Philips
75
BYV99
Philips
75
Max. Reverse Voltage
Rating, V_RRM (Volts)    Package Type
1000
59-04 (axial leaded)
600
Case 403A (surface mount)
1000
DO-204AL (axial leaded)
1000
SOD64 (axial leaded)
1000
SOD57 (axial leaded)
600
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.)
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