BUH315D STMicroelectronics, BUH315D Datasheet - Page 4

• Manufacturer Part Number: BUH315D
• Description: High Voltage Fast-switching Npn Power Transistor
• Manufacturer: STMicroelectronics

BUH315D
4/7
Switching Time Resistive Load at 16 KHz
BASE DRIVE INFORMATION
In order to saturate the power switch and reduce
conduction losses, adequate direct base current
I
100
negative base current I
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
minimizes power losses, fall time t
consequently, T
defined to give total power losses, t
function of I
the optimum negative drive. The test circuit is
illustrated in fig. 1.
B1
has to be provided for the lowest gain h
o
C (line scan phase). On the other hand,
B2
at 16 KHz scanning frequencies
j
. A new set of curves have been
B2
must be provided to
s
and t
B2
f
f
which
FE
and,
as a
at
Inductance L
negative base current I
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:
Where I
flyback voltage, f= frequency of oscillation during
retrace.
1
2
L I
2 f
C
2
C
= operating collector current, V
1
2
L
1
C V
1
C
serves to control the slope of the
CEfly
2
B2
to recombine the
CEfly
=