Semiconductor Components Industries, LLC, 2001
September, 2001 – Rev. 3 1Publication Order Number:
BF256A/D
BF256A
BF256A is a Preferred Device
JFET - General Purpose
N–Channel
N–Channel Junction Field Effect Transistor designed for VHF and
UHF applications.
•Low Cost TO–92 Type Package
•Forward Transfer Admittance, Yfs = 4.5 mmhos (Min)
•Transfer Capacitance – Crss = 0.7 (Typ)
•Power Gain at f = 800 MHz, Typ. = 11 dB
MAXIMUM RATINGS
Rating Symbol Value Unit
Drain–Source Voltage VDS 30 Vdc
Drain–Gate Voltage VDG 30 Vdc
Gate–Source Voltage VGS 30 Vdc
Forward Gate Current IG(f) 10 mAdc
Total Device Dissipation@ TA = 25°C
Derate above 25°C
PD360
2.88 mW
mW/°C
Operating and Storage Channel
Temperature Range Tchannel,
Tstg –65 to +150 °C
0 200
200
25
FREE AIR TEMPERATURE (°C)
PD, MAXIMUM CONTINUOUS
POWER DISSIPATION (mW)
0
Figure 1. Power Derating Curve
500
50
100
300
100 150
400
12575 175
Device Package Shipping
ORDERING INFORMATION
BF256A TO–92
TO–92
CASE 29
STYLE 5
5000 Units/Box
3
2
1
Preferred devices are recommended choices for future use
and best overall value.
Y = Year
WW = Work Week
MARKING DIAGRAMS
BF
256A
YWW
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1 DRAIN
2 SOURCE
3
GATE
BF256A
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2
ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise noted)
Characteristic Symbol Min Typ Max Unit
OFF CHARACTERISTICS
Gate–Source Breakdown Voltage (–IG = –1.0 µAdc, VDS = 0) –V(BR)GSS 30 – — Vdc
Gate–Source Voltage (VDS = 15 Vdc, ID = 200 µA) –VGS 0.5 — 7.5 Vdc
Gate Reverse Current (–VGS = 20 Vdc, VDS = 0) –IGSS — — 5.0 nAdc
ON CHARACTERISTICS
Zero–Gate–Voltage Drain Current (Note 1.) (VDS = 15 Vdc, VGS = 0) IDSS 3.0 – 7.0 mAdc
SMALL–SIGNAL CHARACTERISTICS
Forward Transfer Admittance (VDS = 15 Vdc, VGS = 0, f = 1 kHz) |Yfs| 4.5 5.0 – mmhos
Reverse Transfer Capacitance (VDS = 20 Vdc, –VGS = 1 Vdc, f = 1 MHz) Crss – 0.7 – pF
Output Capacitance (VDS = 20 Vdc, VGS = 0, f = 1 MHz) Coss – 1.0 – pF
Cut–Off Frequency (Note 2.) (VDS = 15 Vdc, VGS = 0) fgfs – 1000 – MHz
1. Pulse Test: Pulse Width = 300 µs, Duty Cycle = 2.0%.
2. The frequency at which gfs is 0.7 of its value at 1 KHz.
025
5
5
IDSS, DRAIN CURRENT (mA) @ VGS = 0
GATE–SOURCE CUTOFF VOLTAGE
(–VGS(off) @ ID = 10 nA)
0
VDS, DRAIN–TO–SOURCE VOLTAGE (VOLTS)
Figure 2. Correlation Between
–VGS(off) and IDSS Figure 3. Drain Current versus
Drain–to–Source Voltage
ID, DRAIN CURRENT (mA)
28 2010
1
6
–VGS = 0 V
10
0
5
2
1215 20 4 6 10 14 16 18
4
1
3
VDS = 15 Vdc
0
4.5
1.5
3.5
0.5
2.5 0.2 V
0.4 V
2
3
4
8
9
7
BF256A
0.6 V
0.8 V
BF256A
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3
f, FREQUENCY (MHz)
Figure 4. Input Admittance versus Frequency
gis, INPUT CONDUCTANCE (mmhos)
1000
0.01
10
10010
0.1
1
Figure 5. Forward Transfer Admittance versus
Frequency
VDS = 15 Vdc
VGS = 0
Yis = gis + jbis
0.1
1
10
100
bis
–gis
bis, INPUT SUSCEPTANCE (mmhos)
f, FREQUENCY (MHz)
gfs, FOR WARD TRANSCONDUCTANCE (mmhos)
1000
0.1
100
10010
1
10
VDS = 15 Vdc
VGS = 0
Yfs = gfs – jbfs
0.1
1
10
100
–bfs
gfs
–bfs, FORWARD SUSCEPTANCE (mmhos)
–VGS, GATE–SOURCE VOLTAGE (VOLTS)
Ciss, INPUT CAPACITANCE (pF)
14 10
VDS = 20 Vdc
f = 1 MHz
0
5
2
623 5 789
4
1
3
0
–VGS, GATE–SOURCE VOLTAGE (VOLTS)
Crss, REVERSE TRANSFER
CAPACITANCE (pF)
28
0
1.0
46 100
0.5
f, FREQUENCY (MHz)
Figure 6. Reverse Transfer Admittance
versus Frequency
–grs, REVERSE TRANSCONDUCTANCE (mmhos)
1000
0.001
1
10010
0.01
0.1
Figure 7. Output Admittance versus
Frequency
VDS = 15 Vdc
VGS = 0
Yrs = –grs – jbrs
0.01
0.1
1
10
–brs –grs
–brs, REVERSE SUSCEPTANCE (mmhos)
f, FREQUENCY (MHz)
gos, OUTPUT CONDUCTANCE (mmhos)
1000
0.001
1
10010
0.01
0.1
VDS = 15 Vdc
VGS = 0
Yos = gos + jbos
0.01
0.1
1
10
bos
gos
bos, OUTPUT SUSCEPTANCE (mmhos)
Figure 8. Input Capacitance versus
Gate–Source Voltage Figure 9. Reverse Transfer Capacitance
versus Gate–Source Voltage
VDS = 20 Vdc
f = 1 MHz
BF256A
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4
PACKAGE DIMENSIONS
CASE 29–11
ISSUE AL
TO–92 (TO–226)
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. CONTOUR OF PACKAGE BEYOND DIMENSION R
IS UNCONTROLLED.
4. LEAD DIMENSION IS UNCONTROLLED IN P AND
BEYOND DIMENSION K MINIMUM.
R
A
P
J
L
B
K
G
H
SECTION X–X
C
V
D
N
N
XX
SEATING
PLANE DIM MIN MAX MIN MAX
MILLIMETERSINCHES
A0.175 0.205 4.45 5.20
B0.170 0.210 4.32 5.33
C0.125 0.165 3.18 4.19
D0.016 0.021 0.407 0.533
G0.045 0.055 1.15 1.39
H0.095 0.105 2.42 2.66
J0.015 0.020 0.39 0.50
K0.500 --- 12.70 ---
L0.250 --- 6.35 ---
N0.080 0.105 2.04 2.66
P--- 0.100 --- 2.54
R0.115 --- 2.93 ---
V0.135 --- 3.43 ---
1
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without further notice to any products herein. SCILLC makes no warranty , representation or guarantee regarding the suitability of its products for any particular
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including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or
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4–32–1 Nishi–Gotanda, Shinagawa–ku, Tokyo, Japan 141–0031
Phone: 81–3–5740–2700
Email: r14525@onsemi.com
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For additional information, please contact your local
Sales Representative.
BF256A/D
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