3-14
Operating Frequency Information
Operating frequency information for a typical device (Figure 13)
is presented as a guide for estimating device performance
for a specific application. Other typical frequency vs collector
current (I
CE
) plots are possible using the information shown
for a typical unit in Figures 4, 7, 8, 11 and 12. The operating
frequency plot (Figure 13) of a typical device shows f
MAX1
or
f
MAX2
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.
f
MAX1
is defined by f
MAX1
= 0.05/(t
D(OFF)I
+ t
D(ON)I
). Dead-
time (the denominator) has been arbitrarily held to 10% of
the on- state time for a 50% duty factor. Other definitions are
possible. t
D(OFF)I
and t
D(ON)I
are defined in Figure 21.
Device turn-off delay can establish an additional frequency
limiting condition for an application other than T
JMAX
.
t
D(OFF)I
is important when controlling output ripple under a
lightly loaded condition.
f
MAX2
is defined by f
MAX2
= (P
D
- P
C
)/(E
OFF
+ E
ON
). The
allowable dissipation (P
D
) is defined by P
D
= (T
JMAX
-
T
C
)/R
θ
JC
. The sum of device switching and conduction
losses must not exceed P
D
. A 50% duty factor was used
(Figure 13) and the conduction losses (P
C
) are approxi-
mated by P
C
= (V
CE
x I
CE
)/2.
E
ON
and E
OFF
are defined in the switching waveforms
shown in Figure 21. E
ON
is the integral of the instantaneous
power loss (I
CE
x V
CE
) during turn-on and E
OFF
is the inte-
gral of the instantaneous power loss during turn-off. All tail
losses are included in the calculation for E
OFF
; i.e. the col-
lector current equals zero (I
CE
= 0).
FIGURE 18. DIODE FORWARD CURRENT AS A FUNCTION OF
FORWARD VOLTAGE DROP
FIGURE 19. RECOVERY TIMES AS A FUNCTION OF FORWARD
CURRENT
Typical Performance Curves
(Continued)
0.5
1.0
1.5
2.5
3.0
I
E
,
V
EC
, FORWARD VOLTAGE (V)
0
2.0
3
0
6
9
12
15
25
o
C
150
o
C
3.5
100
o
C
30
25
20
15
0
t
R
,
I
EC
, FORWARD CURRENT (A)
1
4
t
rr
T
C
= 25
o
C, dI
EC
/dt = 200A/
μ
s
0.5
t
B
5
10
t
A
Test Circuit and Waveform
FIGURE 20. INDUCTIVE SWITCHING TEST CIRCUIT
FIGURE 21. SWITCHING TEST WAVEFORMS
R
G
= 82
L = 1mH
V
DD
= 480V
+
-
RHRD460
t
FI
t
D(OFF)I
t
RI
t
D(ON)I
10%
90%
10%
90%
V
CE
I
CE
V
GE
E
OFF
E
ON
HGTP3N60C3D, HGT1S3N60C3D, HGT1S3N60C3DS