5
Motorola TMOS Power MOSFET Transistor Device Data
V
V
DRAIN–TO–SOURCE DIODE CHARACTERISTICS
VSD, SOURCE–TO–DRAIN VOLTAGE (VOLTS)
Figure 8. Gate–To–Source and Drain–To–Source
Voltage versus Total Charge
I
Figure 9. Resistive Switching Time
Variation versus Gate Resistance
RG, GATE RESISTANCE (OHMS)
1
10
100
t
VDD = 30 V
ID = 52 A
VGS = 10 V
TJ = 25
°
C
Figure 10. Diode Forward Voltage versus Current
0
QT, TOTAL CHARGE (nC)
20
40
60
80
140
ID = 52 A
TJ = 25
°
C
1000
100
10
1
12
6
2
0
8
4
36
33
30
27
24
21
18
15
12
9
6
3
0
QT
Q2
Q1
Q3
VGS
VDS
td(on)
td(off)
tf
tr
VGS = 0 V
TJ = 25
°
C
50
45
40
35
30
25
20
15
10
5
0
0.5
0.6
0.7
0.8
0.9
1
10
1.1
100
120
55
0.4
0.3
0.2
SAFE OPERATING AREA
The Forward Biased Safe Operating Area curves define
the maximum simultaneous drain–to–source voltage and
drain current that a transistor can handle safely when it is
forward biased. Curves are based upon maximum peak
junction temperature and a case temperature (TC) of 25
°
C.
Peak repetitive pulsed power limits are determined by using
the thermal response data in conjunction with the procedures
discussed in AN569, “Transient Thermal Resistance–General
Data and Its Use.”
Switching between the off–state and the on–state may
traverse any load line provided neither rated peak current
(IDM) nor rated voltage (VDSS) is exceeded and the transition
time (tr,tf) do not exceed 10
μ
s. In addition the total power
averaged over a complete switching cycle must not exceed
(TJ(MAX) – TC)/(R
θ
JC).
A Power MOSFET designated E–FET can be safely used
in switching circuits with unclamped inductive loads. For
reliable operation, the stored energy from circuit inductance
dissipated in the transistor while in avalanche must be less
than the rated limit and adjusted for operating conditions
differing from those specified. Although industry practice is to
rate in terms of energy, avalanche energy capability is not a
constant. The energy rating decreases non–linearly with an
increase of peak current in avalanche and peak junction
temperature.
Although many E–FETs can withstand the stress of
drain–to–source avalanche at currents up to rated pulsed
current (IDM), the energy rating is specified at rated
continuous current (ID), in accordance with industry custom.
The energy rating must be derated for temperature as shown
in the accompanying graph (Figure 12). Maximum energy at
currents below rated continuous ID can safely be assumed to
equal the values indicated.