IHD215 CT-Concept Technologie AG, IHD215 Datasheet - Page 13

• Manufacturer Part Number: IHD215
• Description: Intelligent Half-bridge Drivers For Igbts And Power Mosfets
• Manufacturer: CT-Concept Technologie AG

Fig. 6 Principle of the Vce monitoring
of the activated transistor plus that of the
diode and the voltage drop at Rme. Rme
attenuates the reverse current peaks of the
measurement diode Dme and should be
set to 68 .
It should be noted that the power transis-
tors do not turn on immediately - for
IGBTs in particular, several microseconds
may elapse before they have completely
switched through. In conjunction with the
integrated pull-up resistor and the exter-
nal capacitor (Cme), this leads to a delay
in the measurement after the power tran-
sistor is turned on. This delay shall
henceforth be called the response time.
The longer it takes the power transistors to
turn on, the higher must the selected
response time (and thus Cme) be. The
formula for dimensioning Cme can be
found on page 16.
It should also be borne in mind that nega-
tive voltages are not permitted at the
measurement input.
Pin 31 pin 20
Terminal Cb1 Cb2
After the current monitoring circuit has
I n t e r n e t :
w w w . I G B T - D r i v e r . c o m
Data Sheet & Application Manual
responded, the power transistor is turned
off by the protection function of the intelli-
gent driver and remains blocked in this
state for a defined minimum time. This
function is used to protect the component
from thermal overload under a continuous
or recurring short-circuit. This blocking
time can be defined by connecting pin 31
(Cb1) via a capacitor to pin 35 (COM1)
page 16 for the relevant formula). The
capacitance of the blocking capacitor
should not exceed a value of 470nF.
During the blocking period, the response
of the protective function to overcurrent is
signaled at outputs SO1+ and SO1-
After the blocking period has elapsed, the
power transistor is not turned on again
until the following turn-on edge arrives
(see Fig. 7).
Pin 32 pin 21
Terminal REF1 REF2
An external zener diode is connected to
this pin as a reference. It defines the
maximum voltage drop across the acti-
vated power transistor at which the
protective function of the drive circuit is
activated and thus the power transistor is
turned off.
The protective functions of the intelligent
half-bridge drivers of the IHD series
always become active when the voltage at
ME1
drain/collector) is higher than that at
REF1 REF2 (see Figs. 6 & 7).
The reference potential is pin 33 (E1). The
reference may not be blocked by capaci-
tors under any circumstances.
IHD 215/280/680
or pin 20 (Cb2) to Pin 24 (COM2) (see
SO2+ and SO2- .
ME2
(measurement
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