SKHI61 Datasheet, PDF (6/8 Pages) Semikron International – Sixpack IGBT and MOSFET Driver

• V_CE-threshold : 4,8 V
• Interlocking time : 2 µs
• Error blanking time for V_CE-threshold : 4 µs
15
Application Hints
To adjust different V_CE thresholds there is needed an
additional resistor R_VCE and a capacitor C_VCE for each
switch.
Fig. 6 Maximum cycling frequency at Q_GE = 1000 nC vs
temperature
The application range can be calculated by the average
output current of 20 mA and the repetetive acceptable
peak current of 2 A. It has to be considered that the curves
are valid for Q_gmax = 1 µC only.
The maximum switching frequency f_max may be calculated
with the following formula, the maximum value however
being 50 kHz due to switching reasons:
fmax (kHz) = 2*10⁴ / Q_GE (nC)
Gate resistor :
R_G = 33 Ω
V_CE-threshold resistor: intended U_VCE = 4,8 V
Applying equation 1 R_VCE will result in
R_VCE[kΩ]
=
-----------1---1---,--8---6------------
5,4 - 0,93 ⋅ 4,8
–
4,75[kΩ
]
=
7,9k Ω
Next value taken from the E24-range: 8,25 k. The
threshold voltage is recalculated with 8,25 kΩ.
operating the SKHI 61: besides the operating voltage only
the six driver signals TOP1...BOT3 and the driver error
output signal are connected to the controller on the
primary side. The secondary side is working with the
preset V_CE-threshold of 5,8 V.
Fig. 7 and 8 show examples for connection of a SKHI 71
for the application with MiniSKiiP (SKiiP 32 NAB 12) and
the following adjustments:
• Temperature monitoring of the power semiconductor
V_CE-threshold at 4,82 V.
For the capacitor the blanking time may be calculated as:
t_blanking = 4 µs
C_VCE[nF]
=
----4-----^â‹---⁽--7---2---,--7---5----+-----8---,--2---5---⁾---- – 0,1
(8,25 + 4,75) ⋅ 36,08
=
590pF
Thus there can be chosen a capacitor of 680 pF.
Fig. 7 SKHI 61 block diagram
© by SEMIKRON 23-02-2004
Driver Electronic – PCB Drivers 1927