STMICROELECTRONICS BF257

BF257
BF258-BF259
HIGH VOLTAGE VIDEO AMPLIFIERS
DESCRIPTION
The BF257, BF258 and BF259 are silicon planar
epitaxial NPN transistors in Jedec TO-39 metal
case. They are particularly designed for videooutput
stages in CTV and MTV sets, class A audio output
stages and drivers for horizontal deflection circuits.
TO-39
INTERNAL SCHEMATIC DIAGRAM
ABSOLUTE MAXIMUM RATINGS
Symbol
Value
Parameter
Unit
BF 257 BF258 BF25 9
V CBO
Collector-base Voltage (I E = 0)
160
250
300
V
V CEO
Collector-emitter Voltage (I B = 0)
160
250
300
V
V E BO
Emitter-base Voltage (I C = 0)
IC
5
V
Collector Current
100
mA
200
mA
5
W
I CM
Collector Peak Current
Pt o t
Total Power Dissipation at T amb ≤ 50 °C
T stg
Storage Temperature
– 55 to 200
°C
Tj
Junction Temperature
200
°C
October 1988
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BF257-BF258-BF259
THERMAL DATA
R t h j- cas e
R t h j-amb
Thermal Resistance Junction-case
Thermal Resistance Junction-ambient
Max
Max
°C/W
°C/W
30
175
ELECTRICAL CHARACTERISTICS (T amb = 25 °C unless otherwise specified)
Symbol
I CB O
V (BR)
Parameter
Collector Cutoff Current
(I E = 0)
Test Conditions
for BF257
for BF258
for BF259
V CB = 100 V
V CB = 200 V
V CB = 250 V
Min.
Typ.
Max.
Unit
50
50
50
nA
nA
nA
CB O
Collector-base
Breakdown Voltage
(I E = 0)
I C = 100 µA
for BF257
for BF258
for BF259
160
250
300
V
V
V
V ( BR) CEO *
Collector-emitter
Breakdown Voltage
(I B = 0)
I C = 10 mA
for BF257
for BF258
for BF259
160
250
300
V
V
V
Emittter-base
Breakdown Voltage
(I C = 0)
I E = 100 µA
5
V
Collector-emitter
Saturation Voltage
I C = 30 mA
I B = 6 mA
V (BR)
V CE
EB O
(s at )*
h FE *
*
V
DC Current Gain
I C = 30 mA
V CE = 10 V
fT
Transition Frequency
I C = 15 mA
V CE = 10 V
90
MHz
Cr e
Reverse Capacitance
IC = 0
f = 1 MHz
V CE = 30 V
3
pF
Pulsed : pulse duration = 300 µs, duty cycle = 1 %.
DC Current Gain.
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1
25
BF257-BF258-BF259
Collector Cutoff Current.
Collector-base Capacitance.
Transition Frequency.
Power Rating Chart.
Safe Operating Area.
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BF257-BF258-BF259
TO39 MECHANICAL DATA
mm
inch
DIM.
MIN.
A
TYP.
MAX.
MIN.
12.7
TYP.
MAX.
0.500
B
0.49
0.019
D
6.6
0.260
E
8.5
0.334
F
9.4
0.370
G
5.08
0.200
H
1.2
0.047
I
0.9
0.035
45o (typ.)
L
D
A
G
I
E
F
H
B
L
P008B
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BF257-BF258-BF259
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsability for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may results from its use. No
license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned
in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express
written approval of SGS-THOMSON Microelectonics.
 1994 SGS-THOMSON Microelectronics - All Rights Reserved
SGS-THOMSON Microelectronics GROUP OF COMPANIES
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