BU208A

BU508A/BU508AFI

HIGH VOLTAGE FAST-SWITCHING

NPN POWER TRANSISTORS

•– 

STMicroelectronics PREFERRED
SALESTYPES

•– 

HIGH VOLTAGE CAPABILITY (> 1500 V) 

•– 

FULLY INSULATED PACKAGE (U.L.
COMPLIANT) FOR EASY MOUNTING

APPLICATIONS:                                                   

•– 

HORIZONTAL DEFLECTION FOR COLOUR
TV 

DESCRIPTION                                                       
The BU208A, BU508A and BU508AFI are
manufactured using Multiepitaxial Mesa
technology for cost-effective high performance
and use a Hollow Emitter structure to enhance
switching speeds.

INTERNAL  SCHEMATIC  DIAGRAM

April 2002 

ABSOLUTE  MAXIMUM  RATINGS

Symbol

Parameter

Value

Unit

V

CES

Collector-Emitter Voltage (V

BE

 = 0)

1500

V

V

CEO

Collector-Emitter Voltage (I

B

 = 0)

700

V

V

EBO

Emitter-Base Voltage (I

C

 = 0)

10

V

I

C

Collector Current

8

A

I

CM

Collector Peak Current (t

p

 < 5 ms)

15

A

BU208A

BU508A

BU508AFI

TO - 3

TO - 218

ISOWATT218

P

tot

Total Dissipation at T

c

 = 25 

o

C

150

125

50

W

V

isol

Insulation Withstand Voltage (RMS) from All
Three Leads to Exernal Heatsink

2500

V

T

stg

Storage Temperature

-65 to 175 -65 to 150

-65 to 150

o

C

T

j

Max. Operating Junction Temperature

175

150

150

o

C

1

2

3

TO-218                     ISOWATT218

1

2

3

1

2

TO-3

For TO-3 :
C = Tab
E = Pin2.

®

1/8

THERMAL  DATA

TO-3

TO-218

ISOWATT218

R

thj-case

Thermal  Resistance  Junction-case               Max

1

1

2.5

o

C/W

ELECTRICAL  CHARACTERISTICS  (T

case

 = 25 

o

C unless otherwise specified)

Symbol

Parameter

Test Conditions

Min.

Typ.

Max.

Unit

I

CES

Collector Cut-off
Current (V

BE

 = 0)

V

CE

 = 1500 V

V

CE

 = 1500 V              T

C

 = 125 

o

C

1
2

mA
mA

I

EBO

Emitter Cut-off Current
(I

C

 = 0)

V

EB

 = 5 V

100

µ

A

V

CEO(sus)

•ˆ—

Collector-Emitter
Sustaining Voltage
(I

B

 = 0)

I

C

 = 100 mA

700

V

V

EBO

Emitter Base Voltage
(I

C

 = 0)

I

E

 = 10 mA

10

V

V

CE(sat)

•ˆ—

Collector-Emitter
Saturation Voltage

I

C

 = 4.5 A                     I

B

 = 2 A

1

V

V

BE(sat)

•ˆ—

Base-Emitter
Saturation Voltage

I

C

 = 4.5 A                     I

B

 = 2 A

1.3

V

t

s

t

f

INDUCTIVE LOAD
Storage Time
Fall Time

I

C

 = 4.5 A    h

FE

 = 2.5   V

CC

 = 140 V

L

C

 = 0.9 mH    L

B 

= 3 

µ

H

7

550

µ

s

ns

f

T

Transition Frequency

I

C

 = 0.1 A     V

CE

 = 5 V   f = 5 MHz

7

MHz

•ˆ— 

Pulsed: Pulse duration = 300 

µ

s, duty cycle 1.5 %

Safe Operating Area (TO-3)

Safe Operating Areas (TO-218/ISOWATT218)

BU208A / BU508A / BU508AFI

2/8

Derating Curves (TO-3)

DC Current Gain

Base Emitter Saturation Voltage

Derating Curves (TO-218/ISOWATT218)

Collector Emitter Saturation Voltage

Switching Time Inductive Load

BU208A / BU508A / BU508AFI

3/8

Figure 1: Inductive Load Switching Test Circuit.

Switching Time Inductive Load

 

BU208A / BU508A / BU508AFI

4/8

DIM.

mm

inch

MIN.

TYP.

MAX.

MIN.

TYP.

MAX.

A

11.00

 13.10

0.433

 0.516

B

0.97

 1.15

0.038

 0.045

C

1.50

 1.65

0.059

 0.065

D

8.32

 8.92

0.327

 0.351

E

19.00

 20.00

0.748

 0.787

G

10.70

 11.10

0.421

 0.437

N

16.50

 17.20

0.649

 0.677

P

25.00

 26.00

0.984

 1.023

R

4.00

 4.09

0.157

 0.161

U

38.50

 39.30

1.515

 1.547

V

30.00

 30.30

1.187

 1.193

E

B

R

C

D

A

P

G

N

V

U

O

P003F

TO-3 MECHANICAL DATA

BU208A / BU508A / BU508AFI

5/8

DIM.

mm

inch

MIN.

TYP.

MAX.

MIN.

TYP.

MAX.

A

4.7

4.9

0.185

0.193

C

1.17

1.37

0.046

0.054

D

2.5

0.098

E

0.5

0.78

0.019

0.030

F

1.1

1.3

0.043

0.051

G

10.8

11.1

0.425

0.437

H

14.7

15.2

0.578

0.598

L2

-

16.2 -

0.637

L3

18

0.708

L5

3.95

4.15

0.155

0.163

L6

31

1.220

R

-

12.2

-

0.480

Ø 4

4.1

0.157

0.161

R

A

C

D

E

H

F

G

L6

¯

L3

L2

L5

1 2 3

TO-218 (SOT-93) MECHANICAL DATA

P025A

BU208A / BU508A / BU508AFI

6/8

DIM.

mm

inch

MIN.

TYP.

MAX.

MIN.

TYP.

MAX.

A

5.35

5.65

0.211

0.222

C

3.30

3.80

0.130

0.150

D

2.90

3.10

0.114

0.122

D1

1.88

2.08

0.074

0.082

E

0.75

0.95

0.030

0.037

F

1.05

1.25

0.041

0.049

F2

1.50

1.70

0.059

0.067

F3

1.90

2.10

0.075

0.083

G

10.80

11.20

0.425

0.441

H

15.80

16.20

0.622

0.638

L

9

0.354

L1

20.80

21.20

0.819

0.835

L2

19.10

19.90

0.752

0.783

L3

22.80

23.60

0.898

0.929

L4

40.50

42.50

1.594

1.673

L5

4.85

5.25

0.191

0.207

L6

20.25

20.75

0.797

0.817

N

2.1

2.3

0.083

0.091

R

4.6

0.181

DIA

3.5

3.7

0.138

0.146

P025C/A

ISOWATT218 MECHANICAL DATA

- Weight : 4.9 g (typ.)
- Maximum Torque (applied to mounting flange) Recommended: 0.8 Nm;   Maximum: 1 Nm
- The side of the dissipator must be flat within 80 

µ

m

BU208A / BU508A / BU508AFI

7/8

Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is
granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication are
subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products
are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.

The ST logo is a trademark of STMicroelectronics

© 2002 STMicroelectronics - Printed in Italy - All Rights Reserved

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BU208A / BU508A / BU508AFI

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