®
BUH315
HIGH VOLTAGE FAST-SWITCHING
NPN POWER TRANSISTOR
s
s
s
STMicroelectronics PREFERRED
SALESTYPE
HIGH VOLTAGE CAPABILITY
U.L. RECOGNISED ISOWATT218 PACKAGE
(U.L. FILE # E81734 (N)).
APPLICATIONS:
s
HORIZONTAL DEFLECTION FOR COLOUR
TV
s
SWITCH MODE POWER SUPPLIES
3
2
1
ISOWATT218
DESCRIPTION
The BUH315 is manufactured using Multiepitaxial
Mesa technology for cost-effective high
performance and uses a Hollow Emitter structure
to enhance switching speeds.
The BUH series is designed for use in horizontal
deflection circuits in televisions and monitors.
INTERNAL SCHEMATIC DIAGRAM
ABSOLUTE MAXIMUM RATINGS
Symbol
V
CBO
V
CEO
V
EBO
I
C
I
CM
I
B
I
BM
P
t ot
T
stg
T
j
Parameter
Collector-Base Voltage (I
E
= 0)
Collector-Emitter Voltage (I
B
= 0)
Emitter-Base Voltage (I
C
= 0)
Collector Current
Collector Peak Current (t
p
< 5 ms)
Base Current
Base Peak Current (t
p
< 5 ms)
Total Dissipation at T
c
= 25 C
St orage Temperature
Max. Operating Junction Temperature
o
Value
1500
700
10
6
12
3
5
44
-65 to 150
150
Uni t
V
V
V
A
A
A
A
W
o
o
C
C
1/7
November 1999
BUH315
THERMAL DATA
R
t hj-ca se
Thermal Resistance Junction-case
Max
2.8
o
C/W
ELECTRICAL CHARACTERISTICS
(T
case
= 25
o
C unless otherwise specified)
Symb ol
I
CES
I
EBO
Parameter
Collector Cut-off
Current (V
BE
= 0)
Emitter Cut-off Current
(I
C
= 0)
Test Cond ition s
V
CE
= 1500 V
V
EB
= 5 V
I
C
= 100 mA
700
Min.
Typ .
Max.
200
100
Un it
µA
µA
V
V
CEO(sus )
∗
Collector-Emitter
Sustaining Voltage
(I
B
= 0)
V
EBO
V
CE(sat )
∗
V
BE(s at)
∗
h
F E
∗
Emitter-Base Voltage
(I
C
= 0)
Collector-Emitter
Saturation Voltage
Base-Emitt er
Saturation Voltage
DC Current Gain
RESISTIVE LO AD
Storage Time
Fall Time
INDUCTIVE LO AD
Storage Time
Fall Time
I
E
= 10 mA
I
C
= 3 A
I
C
= 3 A
I
C
= 3 A
I
C
= 3 A
I
B
= 0.75 A
I
B
= 0.75 A
V
CE
= 5 V
V
CE
= 5 V
10
1.5
1.3
6
3.5
1.6
110
3.5
340
12
V
V
V
T
j
= 100 C
o
t
s
t
f
t
s
t
f
V
CC
= 400 V
I
B1
= 0.75 A
I
C
= 3 A
I
B1
= 0.75 A
I
C
= 3 A
I
B2
= 1.5 A
2.4
200
µs
ns
µs
ns
f = 15625 Hz
I
B2
= -1.5 A
π
6
V
c eflybac k
= 1050 sin
10
t V
5
f = 31250 Hz
I
B2
= -1.5 A
π
V
c eflybac k
= 1200 sin
10
6
t V
5
I
C
= 3 A
I
B1
= 0.75 A
t
s
t
f
INDUCTIVE LO AD
Storage Time
Fall Time
3.5
270
µs
ns
∗
Pulsed: Pulse duration = 300
µs,
duty cycle 1.5 %
Safe Operating Area
Thermal Impedance
2/7
BUH315
Power Losses at 32 KHz
Switching Time Inductive Load at 32 KHz
(see figure 2)
Reverse Biased SOA
BASE DRIVE INFORMATION
In order to saturate the power switch and reduce
conduction losses, adequate direct base current
I
B1
has to be provided for the lowest gain h
FE
at
100
o
C (line scan phase). On the other hand,
negative base current I
B2
must be provided to
turn off the power transistor (retrace phase).
Most of the dissipation, in the deflection
application, occurs at switch-off. Therefore it is
essential to determine the value of I
B2
which
minimizes power losses, fall time t
f
and,
consequently, T
j
. A new set of curves have been
defined to give total power losses, t
s
and t
f
as a
function of I
B2
at both 16 KHz and 32 KHz
scanning frequencies for choosing the optimum
negative drive. The test circuit is illustrated in
4/7
figure 1.
Inductance L
1
serves to control the slope of the
negative base current I
B2
to recombine the
excess carrier in the collector when base current
is still present, this would avoid any tailing
phenomenon in the collector current.
The values of L and C are calculated from the
following equations:
1
1
1
L
(
I
C
)
2
=
C
(
V
CEfly
)
2
ω =
2
π
f
=
2
2
L
√
C
Where I
C
= operating collector current, V
CEfly
=
flyback voltage, f= frequency of oscillation during
retrace.
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