L = 50µH
1/RG = 1/RGEN + 1/RGE
RGEN = 50Ω
RGE = 50Ω
FIGURE 12. INDUCTIVE SWITCHING TEST CIRCUIT
Operating Frequency Information
Handling Precautions for IGBTs
Operating frequency information for a typical device (Figure
10) is presented as a guide for estimating device performance
for a speciﬁc application. Other typical frequency vs collector
current (ICE) plots are possible using the information shown
for a typical unit in Figures 7, 8 and 9. The operating
frequency plot (Figure 10) of a typical device shows fMAX1 or
fMAX2 whichever is smaller at each point. The information is
based on measurements of a typical device and is bounded
by the maximum rated junction temperature.
fMAX1 is deﬁned by fMAX1 = 0.05/tD(OFF)I. tD(OFF)I deadtime
(the denominator) has been arbitrarily held to 10% of the on-
state time for a 50% duty factor. Other deﬁnitions are
possible. tD(OFF)I is deﬁned as the time between the 90%
point of the trailing edge of the input pulse and the point
where the collector current falls to 90% of its maximum
value. Device turn-off delay can establish an additional fre-
quency limiting condition for an application other than TJMAX.
tD(OFF)I is important when controlling output ripple under a
lightly loaded condition. fMAX2 is deﬁned by fMAX2 = (Pd - Pc)/
WOFF. The allowable dissipation (Pd) is deﬁned by Pd =
(TJMAX - TC)/RθJC. The sum of device switching and conduc-
tion losses must not exceed Pd. A 50% duty factor was used
(Figure 10) and the conduction losses (Pc) are approximated
by Pc = (VCE • ICE)/2. WOFF is deﬁned as the integral of the
instantaneous power loss starting at the trailing edge of the
input pulse and ending at the point where the collector
current equals zero (ICE = 0A).
The switching power loss (Figure 10) is deﬁned as fMAX2 •
WOFF. Turn-on switching losses are not included because
they can be greatly inﬂuenced by external circuit conditions
Insulated Gate Bipolar Transistors are susceptible to gate-
insulation damage by the electrostatic discharge of energy
through the devices. When handling these devices, care
should be exercised to assure that the static charge built in
the handler’s body capacitance is not discharged through
the device. With proper handling and application procedures,
however, IGBTs are currently being extensively used in
production by numerous equipment manufacturers in
military, industrial and consumer applications, with virtually
no damage problems due to electrostatic discharge. IGBTs
can be handled safely if the following basic precautions are
1. Prior to assembly into a circuit, all leads should be kept
shorted together either by the use of metal shorting
springs or by the insertion into conductive material such
as “† ECCOSORBD LD26” or equivalent.
2. When devices are removed by hand from their carriers,
the hand being used should be grounded by any suitable
means - for example, with a metallic wristband.
3. Tips of soldering irons should be grounded.
4. Devices should never be inserted into or removed from
circuits with power on.
5. Gate Voltage Rating - Never exceed the gate-voltage
rating of VGEM. Exceeding the rated VGE can result in
permanent damage to the oxide layer in the gate region.
6. Gate Termination - The gates of these devices are
essentially capacitors. Circuits that leave the gate open-
circuited or ﬂoating should be avoided. These conditions
can result in turn-on of the device due to voltage buildup
on the input capacitor due to leakage currents or pickup.
7. Gate Protection - These devices do not have an internal
monolithic zener diode from gate to emitter. If gate
protection is required an external zener is recommended.
† Trademark Emerson and Cumming, Inc.