BF245A Datasheet BF245A, BF245B | P1-P3

JFET VHF/UHF Amplifiers

N–Channel — Depletion

MAXIMUM RATINGS

Rating Symbol Value Unit

Drain–Source Voltage V

DS

±30 Vdc

Drain–Gate Voltage V

DG

30 Vdc

Gate–Source Voltage V

GS

30 Vdc

Drain Current I

D

100 mAdc

Forward Gate Current I

G(f)

10 mAdc

Total Device Dissipation @ T

A

= 25°C

Derate above 25°C

P

D

350

2.8

mW

mW/°C

Storage Channel Temperature Range T

stg

–65 to +150 °C

3 DRAIN

1 SOURCE

2

GATE

3 DRAIN

2 SOURCE

1

GATE

STYLE 22 STYLE 23

ELECTRICAL CHARACTERISTICS (T

A

= 25°C unless otherwise noted)

Characteristic

Symbol Min Typ Max Unit

OFF CHARACTERISTICS

Gate–Source Breakdown Voltage

(I

G

= 1.0 µAdc, V

DS

= 0)

V

(BR)GSS

30 — — Vdc

Gate–Source

(V

DS

= 15 Vdc, I

D

= 200 µAdc) BF245

(1)

BF245A, BF244A

(2)

BF245B, BF244B

BF245C

V

GS

0.4

1.6

3.2

—

7.5

2.2

3.8

7.5

Vdc

Gate–Source Cutoff Voltage

(V

DS

= 15 Vdc, I

D

= 10 nAdc)

V

GS(off)

–0.5 — –8.0 Vdc

Gate Reverse Current

(V

GS

= 20 Vdc, V

DS

= 0)

I

GSS

— — 5.0 nAdc

ON CHARACTERISTICS

Zero–Gate–Voltage Drain Current

(V

DS

= 15 Vdc, V

GS

= 0) BF245

(1)

BF245A, BF244A

(2)

BF245B, BF244B

BF245C

I

DSS

2.0

6.0

12

—

25

6.5

15

25

mAdc

1. On orders against the BF245, any or all subgroups might be shipped.

2. On orders against the BF244A, any or all subgroups might be shipped.

ON Semiconductor

 Semiconductor Components Industries, LLC, 2001

June, 2001 – Rev. 0

1 Publication Order Number:

BF245A/D

BF245A

BF245B

BF244A, BF244B

CASE 29–11, STYLE 22

TO–92 (TO–226AA)

1

2

3

BF245, BF245A,

BF245B, BF245C

CASE 29–11, STYLE 23

TO–92 (TO–226AA)

1

2

3

BF245A BF245B

http://onsemi.com

2

ELECTRICAL CHARACTERISTICS (T

A

= 25°C unless otherwise noted) (Continued)

Characteristic Symbol Min Typ Max Unit

SMALL–SIGNAL CHARACTERISTICS

Forward Transfer Admittance (V

DS

= 15 Vdc, V

GS

= 0, f = 1.0 kHz) Y

fs

 3.0 — 6.5 mmhos

Output Admittance (V

DS

= 15 Vdc, V

GS

= 0, f = 1.0 kHz) Y

os

 — 40 — mhos

Forward Transfer Admittance (V

DS

= 15 Vdc, V

GS

= 0, f = 200 MHz) Y

fs

 — 5.6 — mmhos

Reverse Transfer Admittance (V

DS

= 15 Vdc, V

GS

= 0, f = 200 MHz) Y

rs

 — 1.0 — mmhos

Input Capacitance (V

DS

= 20 Vdc, –V

GS

= 1.0 Vdc) C

iss

— 3.0 — pF

Reverse Transfer Capacitance (V

DS

= 20 Vdc, –V

GS

= 1.0 Vdc, f = 1.0 MHz) C

rss

— 0.7 — pF

Output Capacitance (V

DS

= 20 Vdc, –V

GS

= 1.0 Vdc, f = 1.0 MHz) C

oss

— 0.9 — pF

Cut–off Frequency

(3)

(V

DS

= 15 Vdc, V

GS

= 0) F

(Yfs)

— 700 — MHz

3. The frequency at which g

fs

is 0.7 of its value at 1 kHz.

f, FREQUENCY (MHz)

30

10

b

is

@ I

DSS

f, FREQUENCY (MHz)

5.0

Figure 1. Input Admittance (y

is

) Figure 2. Reverse Transfer Admittance (y

rs

)

COMMON SOURCE CHARACTERISTICS

ADMITTANCE PARAMETERS

(V

DS

= 15 Vdc, T

channel

= 25°C)

f, FREQUENCY (MHz)

20

f, FREQUENCY (MHz)

10

Figure 3. Forward Transadmittance (y

fs

) Figure 4. Output Admittance (y

os

)

g

is

, INPUT CONDUCTANCE (mmhos)

20

10

0.3

0.5

0.7

1.0

2.0

3.0

5.0

7.0

20 30 50 70 100 200 300

500 700

1000

b

is

, INPUT SUSCEPTANCE (mmhos)

g

fs

, FORWARD TRANSCONDUCTANCE (mmhos)

|b

fs

|, FORWARD SUSCEPTANCE (mmhos)

g

rs

, REVERSE TRANSADMITTANCE (mmhos)

b

rs

, REVERSE SUSCEPTANCE (mmhos)

0.2

0.3

0.5

0.7

1.0

2.0

3.0

5.0

7.0

10

g

os

, OUTPUT ADMITTANCE (mhos)

b

os

, OUTPUT SUSCEPTANCE (mhos)

3.0

0.05

0.07

0.1

0.2

0.3

0.7

0.5

1.0

2.0

10 20 30 50 70 100 200 300

500 700

1000

10 20 30 50 70 100 200 300

500 700

1000

0.01

0.02

0.05

0.1

0.2

0.5

1.0

2.0

5.0

10 20 30 50 70 100 200 300

500 700

1000

b

is

@ 0.25 I

DSS

g

is

@ I

DSS

g

is

@ 0.25 I

DSS

b

rs

@ I

DSS

0.25 I

DSS

g

rs

@ I

DSS

, 0.25 I

DSS

g

fs

@ I

DSS

|b

fs

| @ I

DSS

|b

fs

| @ 0.25 I

DSS

b

os

@ I

DSS

and 0.25 I

DSS

g

os

@ I

DSS

g

os

@ 0.25 I

DSS

g

fs

@ 0.25 I

DSS

BF245A BF245B

http://onsemi.com

3

Figure 5. S

11s

Figure 6. S

12s

0° 350° 340° 330°10°20°30°

180° 190° 200° 210°170°160°150°

3

2

31

3

0

2

9

2

8

2

7

2

6

2

5

2

4

2

3

2

40°

50°

60°

70°

80°

90°

100°

110°

120°

130°

140°

0° 350° 340° 330°10°20°30°

180° 190° 200° 210°170°160°150°

320°

310°

300°

290°

280°

270°

260°

250°

240°

230°

220°

40°

50°

60°

70°

80°

90°

100°

110°

120°

130°

140°

0° 350° 340° 330°10°20°30°

180° 190° 200° 210°170°160°150°

3

2

31

3

0

2

9

2

8

2

7

2

6

2

5

2

4

2

3

2

40°

50°

60°

70°

80°

90°

100°

110°

120°

130°

140°

0° 350° 340° 330°10°20°30°

180° 190° 200° 210°170°160°150°

320°

310°

300°

290°

280°

270°

260°

250°

240°

230°

220°

40°

50°

60°

70°

80°

90°

100°

110°

120°

130°

140°

1.0

0.9

0.8

0.7

0.6

0.4

0.3

0.2

0.1

0.0

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.4

0.5

0.6

900

800

700

600

500

400

300

200

100

800

700

600

500

400

300

200

100

I

D

= 0.25 I

DSS

I

D

= I

DSS

100

200

300

400

600

700

800

900

500

I

D

= I

DSS

, 0.25 I

DSS

900

500

800

700

600

500

400

300

200

100

I

D

= 0.25 I

DSS

I

D

= I

DSS

100

200

300

400

900

600

700

800

900

800

600

400

300

200

100

I

D

= 0.25 I

DSS

I

D

= I

DSS

900

100

500

700

300

400

500

600

700

800

Figure 7. S

21s

Figure 8. S

22s

COMMON SOURCE CHARACTERISTICS

S–PARAMETERS

(V

DS

= 15 Vdc, T

channel

= 25°C, Data Points in MHz)

BF245A

BF245A

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