Datasheet BLF245B Datasheet (Philips)

DISCRETE SEMICONDUCTORS

DATA SH EET

BLF245B

VHF push-pull power MOS
transistor

Product specification

September 1992

Philips Semiconductors Product specification

VHF push-pull power MOS transistor BLF245B

FEATURES

• High power gain

• Easy power control

• Good thermal stability

• Gold metallization ensures

excellent reliability.

DESCRIPTION

Dual push-pull silicon N-channel
enhancement mode vertical D-MOS
transistor designed for large signal
amplifier applications in the VHF
frequency range.

The transistor is encapsulated in a
4-lead, SOT279 balanced flange
envelope, with a ceramic cap. The
mounting flange provides the
common source connection for the
transistors.

PINNING - SOT279

PIN DESCRIPTION

1 gate 1
2 drain 1
3 gate 2
4 drain 2
5 source

PIN CONFIGURATION

page

Top view

14

5

32

MSB018

d

2

g

2

g

1

MBB157

s

d

1

Fig.1 Simplified outline and symbol.

CAUTION

The device is supplied in an antistatic package. The gate-source input must
be protected against static charge during transport and handling.

WARNING

Product and environmental safety - toxic materials

This product contains beryllium oxide. The product is entirely safe provided
that the BeO disc is not damaged. All persons who handle, use or dispose of
this product should be aware of its nature and of the necessary safety
precautions. After use, dispose of as chemical or special waste according to
the regulations applying at the location of the user. It must never be thrown
out with the general or domestic waste.

QUICK REFERENCE DATA

RF performance at T

MODE OF OPERATION

= 25 °C in a push-pull common source test circuit.

h

f

(MHz)

V

(V)

DS

P

(W)

L

G

P

(dB)

(%)

CW, class-B 175 28 30 > 14 > 55

September 1992 2

η

D

Philips Semiconductors Product specification

VHF push-pull power MOS transistor BLF245B

LIMITING VALUES

In accordance with the Absolute Maximum System (IEC 134).
Per transistor section unless otherwise specified.

SYMBOL PARAMETER CONDITIONS MIN. MAX. UNIT

V

DS

±V

GS

I

D

P

tot

T

stg

T

j

THERMAL RESISTANCE

drain-source voltage − 65 V
gate-source voltage − 20 V
DC drain current − 4.5 A
total power dissipation up to Tmb = 25 °C; total device;

− 75 W

both sections equally loaded
storage temperature −65 150 °C
junction temperature − 200 °C

SYMBOL PARAMETER CONDITIONS

R

th j-mb

thermal resistance from

total device; both sections equally loaded 2.3 K/W

junction to mounting base

R

th mb-h

thermal resistance from

total device; both sections equally loaded 0.3 K/W

mounting base to heatsink

2

10

handbook, halfpage

I

D

(A)

10

1

−1

10

1

(1)

10

VDS (V)

MRA922

(2)

2

10

120

handbook, halfpage

P

tot

(W)

80

40

0

04080

THERMAL

RESISTANCE

MRA929

(2)

(1)

120

Th (

160

o

C)

(1) Current in this area may be limited by R
(2) Tmb = 25 °C.
Total device; both sections equally loaded.

DS(on)

.

Fig.2 DC SOAR.

September 1992 3

(1) Continuous operation.
(2) Short-time operation during mismatch.
Total device; both sections equally loaded.

Fig.3 Power/temperature derating curves.

Philips Semiconductors Product specification

VHF push-pull power MOS transistor BLF245B

CHARACTERISTICS (per section)

T

= 25 °C unless otherwise specified.

j

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

V

(BR)DSS

I

DSS

I

GSS

V

GS(th)

g

fs

R

DS(on)

I

DSX

C

is

C

os

C

rs

drain-source breakdown voltage ID = 5 mA; VGS = 0 65 −−V
drain-source leakage current VGS = 0; VDS = 28 V −−1mA
gate-source leakage current ±VGS = 20 V; VDS = 0 −−1µA
gate-source threshold voltage ID = 5 mA; VDS = 10 V 2 − 4.5 V
forward transconductance ID = 0.75 A; VDS = 10 V 600 850 − mS
drain-source on-state resistance ID = 0.75 A; VGS = 10 V − 0.8 1.5 Ω
on-state drain current VGS = 10 V; VDS = 10 V − 5 − A
input capacitance VGS = 0; VDS = 28 V; f = 1 MHz − 60 − pF
output capacitance VGS = 0; VDS = 28 V; f = 1 MHz − 40 − pF
feedback capacitance VGS = 0; VDS = 28 V; f = 1 MHz − 4.5 − pF

handbook, halfpage

2

T.C.

(mV/K)

0

−2

−4

−6

−8

1

VDS= 10 V.

10 10

2

ID (mA)

Fig.4 Temperature coefficient of gate-source

voltage as a function of drain current, typical
values per section.

MGP180

12

MGP181

VGS (V)

handbook, halfpage

3

10

6

I

D

(A)

4

2

0

048 16

VDS= 10 V.

Tj = 25 °C

125 °C

Fig.5 Drain current as a function of gate-source

voltage, typical values per section.

September 1992 4

Philips Semiconductors Product specification

VHF push-pull power MOS transistor BLF245B

handbook, halfpage

2

R

DS(on)

(Ω)

1

0

0

ID= 0.75 A; VGS= 10 V

40 80 160120

Tj (°C)

Fig.6 Drain-source on-state resistance as a

function of junction temperature, typical
values per section.

MGP182

160

handbook, halfpage

C

(pF)

120

80

40

0

01020 40

VGS= 0; f = 1 MHz.

C

is

C

os

MGP183

30

V

(V)

DS

Fig.7 Input and output capacitance as functions

of drain-source voltage, typical values per
section.

20

handbook, halfpage

C

rs

(pF)

10

0

01020 40

VGS= 0; f = 1 MHz.

30

V

DS

Fig.8 Feedback capacitance as a function of

drain-source voltage, typical values per
section.

MGP184

(V)

September 1992 5

Philips Semiconductors Product specification

VHF push-pull power MOS transistor BLF245B

APPLICATION INFORMATION FOR CLASS-B OPERATION

T

= 25 °C; R

h

RF performance in a push-pull, common source, class-B test circuit.

= 0.3 K/W; unless otherwise specified.

th mb-h

MODE OF OPERATION

f

(MHz)

V

(V)

DS

I

DQ

(mA)

P

(W)

L

G

(dB)

CW, class-B 175 28 2 × 25 30 > 14

typ. 18

Ruggedness in class-B operation

The BLF245B is capable of withstanding a load mismatch
corresponding to VSWR = 50 through all phases, under
the following conditions:

VDS= 28 V, f = 175 MHz at rated output power.

20

handbook, halfpage

G

p

(dB)

15

10

MGP185

G

p

η

D

80

η

D

60

40

40

handbook, halfpage

P

L

(W)

30

20

P

η

D

(%)

> 55

typ. 65

MGP186

5

0

01020 40

Class-B operation; VDS = 28 V; IDQ = 2 × 25 mA;
ZL = 8.8 + j12.7 Ω; f = 175 MHz.

30

PL (W)

20

0

Fig.9 Power gain and efficiency as functions of

output power, typical values.

September 1992 6

10

0

0 0.5 1.0 2.0

Class-B operation; VDS = 28 V; IDQ = 2 × 25 mA;
ZL = 8.8 + j12.7 Ω; f = 175 MHz.

1.5
P

(W)

IN

Fig.10 Load power as a function of input power,

typical values.

Philips Semiconductors Product specification

VHF push-pull power MOS transistor BLF245B

handbook, full pagewidth

+V

R5R3

+V

G

D

C11

C12

50 Ω
input

C7

C8

R1

D.U.T.

L1

C1

L2

C2

L3

L5

L6L4

C5 C6C3 C4 C27

L7L8L9

R2

C10

C9

C13

L10

C14

R7

C15

L14

L16 C25 L20

L12

C21 C22 C23 C24

L17L13

L15

C16

C17

R8

L11

C18

C19

L18

L19

C26

L22

L21

50 Ω

output

C20

MGP187

+V

D

f = 175 MHz.

+V

R6

G

R4

Fig.11 Test circuit for class-B operation.

List of components (see test circuit)

COMPONENT DESCRIPTION VALUE DIMENSIONS CATALOGUE NO.

C1, C2 multilayer ceramic chip capacitor

270 pF

(note 1)

C3 multilayer ceramic chip capacitor

24 pF

(note 1)
C4 film dielectric trimmer 4 to 60 pF 2222 809 08002
C5, C25, C26 multilayer ceramic chip capacitor

91 pF

(note 1)
C6, C22, C24 film dielectric trimmer 5 to 60 pF 2222 809 08003
C7, C9, C12, C14,

multilayer ceramic chip capacitor 100 nF 2222 852 47104
C17, C19

September 1992 7

Philips Semiconductors Product specification

VHF push-pull power MOS transistor BLF245B

COMPONENT DESCRIPTION VALUE DIMENSIONS CATALOGUE NO.

C8, C10 multilayer ceramic chip capacitor

(note 1)
C11, C20 multilayer ceramic chip capacitor 10 nF 2222 852 47103
C13, C18 electrolytic capacitor 10 µF, 63 V
C15, C16 multilayer ceramic chip capacitor

(note 1)
C21, C27 multilayer ceramic chip capacitor

(note 1)
C23 multilayer ceramic chip capacitor

(note 1)
L1, L3, L20, L22 stripline (note 2) 55 Ω length 111 mm

L2, L21 semi-rigid cable 50 Ω length 111 mm

L4, L5 stripline (note 2) 49.5 Ω length 28 mm

L6, L7 stripline (note 2) 49.5 Ω length 22.5 mm

L8, L9 stripline (note 2) 49.5 Ω length 4.5 mm

L10, L11 grade 3B Ferroxcube RF choke 4312 020 36642
L12, L13 stripline (note 2) 49.5 Ω length 21 mm

L14, L15 4 turns enamelled 1 mm copper

wire

L16, L17 stripline (note 2) 49.5 Ω length 30 mm

L18, L19 stripline (note 2) 49.5 Ω length 26 mm

R1, R2 0.4 W metal film resistor 10 Ω
R3, R4 10 turns potentiometer 50 Ω
R5, R6 0.4 W metal film resistor 205 kΩ
R7, R8 0.4 W metal film resistor 10 Ω

680 pF

100 pF

75 pF

36 pF

width 2.5 mm

ext. dia. 2.2 mm

width 3 mm

width 3 mm

width 3 mm

width 3 mm

70 nH length 9 mm

int. dia. 6 mm
leads 2 × 5 mm

width 3 mm

width 3 mm

Notes

1. American Technical Ceramics (ATC) capacitor, type 100B or other capacitor of the same quality.

2. The striplines are on a double copper-clad printed circuit board, with epoxy glass dielectric (εr= 4.5),
thickness1⁄16inch. The other side of the board is fully metallized and used as a ground plane. The ground planes on
each side of the board are connected together by means of copper straps and hollow rivets.

September 1992 8

Philips Semiconductors Product specification

VHF push-pull power MOS transistor BLF245B

handbook, full pagewidth

handbook, full pagewidth

L1 + L2

L3

C1

C2

C3

C4

+V

G

C15

C7
C8

R1

C5
L4
L5

C6

rivet

L6
L7

C27
R2

C10

+V

L8
L9

C9

C16

G

200 mm

L12

L13

C14

L17

C17

L10

L14

L16

C21
C22

L15

L11

+V

+V

D

R7

R8

D

C11

C19

C13

C18

L18
L19

C12

C20

rivet

L20

C25

C23

C24

C26

L21 + L22

MBA378

copper

strap

copper

strap

rivet

copper

strap

copper

strap

The circuit and components are situated on one side of the epoxy fibre-glass board, the other side being fully
metallized to serve as a ground. Earth connections are made by means of copper straps and hollow rivets for a
direct contact between the upper and lower sheets.

copper

strap

copper

strap

Fig.12 Component layout for 175 MHz test circuit.

September 1992 9

copper

strap

rivet

copper

rivetrivet

110 mm

strap

MBA377

Philips Semiconductors Product specification

VHF push-pull power MOS transistor BLF245B

300

MGP188

f (MHz)

10

handbook, halfpage

Z

i

(Ω)

5

r

i

0

x

i

−5

−10

0 100 200 400

Class-B operation; VDS = 28 V; IDQ = 2 × 25 mA;
RGS = 10 Ω;PL= 30 W (total device).

Fig.13 Input impedance as a function of frequency

(series components), typical values per
section.

30

handbook, halfpage

Z

L

(Ω)

20

X

10

R

0

0

Class-B operation; VDS = 28 V; IDQ = 2 × 25 mA;
RGS = 10 Ω;PL= 30 W (total device).

100 200 400300

L

L

MGP189

f (MHz)

Fig.14 Load impedance as a function of frequency

(series components), typical values per
section.

handbook, halfpage

Fig.15 Definition of MOS impedance.

300

MGP190

f (MHz)

25

handbook, halfpage

G

p

(dB)

20

15

10

5

Z

i

Z

MBA379

L

0

0 100 200 400

Class-B operation; VDS = 28 V; IDQ = 2 × 25 mA;
RGS = 10 Ω;PL= 30 W (total device).

Fig.16 Power gain as a function of frequency,

typical values per section.

September 1992 10

Philips Semiconductors Product specification

VHF push-pull power MOS transistor BLF245B

PACKAGE OUTLINE

Flanged double-ended ceramic package; 2 mounting holes; 4 leads SOT279A

D

A

F

5

U

1

q

H

1

1

U2H

A

DIMENSIONS (millimetre dimensions are derived from the original inch dimensions)

1.66

1.39

c

0.16

0.10

0.006

0.004

Db

9.28

9.01

0.365

0.355

UNIT

mm

inches

A

6.84

6.01

0.269

0.237

0.065

0.055

2

b

e

F

e

EU

5.97

5.71

0.235

0.225

3.05

0.12

3.05

2.54

0.120

0.100

w

2

4

3

w

3

0 5 10 mm

H

12.96

11.93

0.51

0.47

M

M

scale

H

1

4.96

4.19

0.195

0.165

C

C

p

p

3.48

3.22

0.137

0.127

B

w

4.35

4.03

0.171

0.159

c

E

M

AB

1

Q

qw

18.42

U

1

24.90

24.63

0.98

0.97

Q

w

1

2

5.97

5.71

0.235

0.225

w

3

2

0.250.51 1.02

0.010.02 0.040.725

OUTLINE
VERSION

SOT279A 97-06-28

IEC JEDEC EIAJ

REFERENCES

EUROPEAN

PROJECTION

September 1992 11

ISSUE DATE

Philips Semiconductors Product specification

VHF push-pull power MOS transistor BLF245B

DEFINITIONS

Data Sheet Status

Objective specification This data sheet contains target or goal specifications for product development.
Preliminary specification This data sheet contains preliminary data; supplementary data may be published later.
Product specification This data sheet contains final product specifications.

Limiting values

Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one or
more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation
of the device at these or at any other conditions above those given in the Characteristics sections of the specification
is not implied. Exposure to limiting values for extended periods may affect device reliability.

Application information

Where application information is given, it is advisory and does not form part of the specification.

LIFE SUPPORT APPLICATIONS

These products are not designed for use in life support appliances, devices, or systems where malfunction of these
products can reasonably be expected to result in personal injury. Philips customers using or selling these products for
use in such applications do so at their own risk and agree to fully indemnify Philips for any damages resulting from such
improper use or sale.

September 1992 12