DISCRETE SEMICONDUCTORS
DATA SHEET
BF245A; BF245B; BF245C
N-channel silicon field-effect
transistors
Product specification
Supersedes data of April 1995
1996 Jul 30
NXP Semiconductors
Product specification
N-channel silicon field-effect transistors
FEATURES
Interchangeability of drain and source connections
Frequencies up to 700 MHz.
APPLICATIONS
LF, HF and DC amplifiers.
DESCRIPTION
General purpose N-channel symmetrical junction
field-effect transistors in a plastic TO-92 variant package.
CAUTION
The device is supplied in an antistatic package. The
gate-source input must be protected against static
discharge during transport or handling.
Fig.1
handbook, halfpage
2
BF245A; BF245B;
BF245C
PINNING
PIN
1
2
3
SYMBOL
d
s
g
drain
source
gate
DESCRIPTION
1
3
g
MAM257
d
s
Simplified outline (TO-92 variant)
and symbol.
QUICK REFERENCE DATA
SYMBOL
V
DS
V
GSoff
V
GSO
I
DSS
PARAMETER
drain-source voltage
gate-source cut-off voltage
gate-source voltage
drain current
BF245A
BF245B
BF245C
P
tot
y
fs
C
rs
total power dissipation
forward transfer admittance
reverse transfer capacitance
T
amb
= 75
C
V
DS
= 15 V; V
GS
= 0;
f = 1 kHz; T
amb
= 25
C
V
DS
= 20 V; V
GS
=
1
V;
f = 1 MHz; T
amb
= 25
C
I
D
= 10 nA; V
DS
= 15 V
open drain
V
DS
= 15 V; V
GS
= 0
2
6
12
3
1.1
6.5
15
25
300
6.5
mA
mA
mA
mW
mS
pF
CONDITIONS
0.25
MIN.
TYP.
MAX.
30
8
30
UNIT
V
V
V
1996 Jul 30
2
NXP Semiconductors
Product specification
N-channel silicon field-effect transistors
LIMITING VALUES
In accordance with the Absolute Maximum Rating System (IEC 134).
SYMBOL
V
DS
V
GDO
V
GSO
I
D
I
G
P
tot
T
stg
T
j
Note
PARAMETER
drain-source voltage
gate-drain voltage
gate-source voltage
drain current
gate current
total power dissipation
storage temperature
operating junction temperature
up to T
amb
= 75
C;
open source
open drain
BF245A; BF245B; BF245C
CONDITIONS
up to T
amb
= 90
C;
note 1
MIN.
MAX.
30
30
30
25
10
300
300
+150
150
V
V
V
UNIT
mA
mA
mW
mW
C
C
65
1. Device mounted on a printed-circuit board, minimum lead length 3 mm, mounting pad for drain lead minimum
10 mm
10 mm.
THERMAL CHARACTERISTICS
SYMBOL
R
th j-a
PARAMETER
thermal resistance from junction to ambient
thermal resistance from junction to ambient
STATIC CHARACTERISTICS
T
j
= 25
C;
unless otherwise specified.
SYMBOL
V
(BR)GSS
V
GSoff
V
GS
PARAMETER
gate-source breakdown voltage
gate-source cut-off voltage
gate-source voltage
BF245A
BF245B
BF245C
I
DSS
drain current
BF245A
BF245B
BF245C
I
GSS
gate cut-off current
V
GS
=
20
V; V
DS
= 0
V
GS
=
20
V; V
DS
= 0; T
j
= 125
C
Note
1. Measured under pulse conditions: t
p
= 300
s;
0.02.
V
DS
= 15 V; V
GS
= 0; note 1
2
6
12
6.5
15
25
5
0.5
mA
mA
mA
nA
A
CONDITIONS
I
G
=
1 A;
V
DS
= 0
I
D
= 10 nA; V
DS
= 15 V
I
D
= 200
A;
V
DS
= 15 V
0.4
1.6
3.2
2.2
3.8
7.5
V
V
V
MIN.
30
0.25
8.0
MAX.
V
V
UNIT
CONDITIONS
in free air
VALUE
250
200
UNIT
K/W
K/W
1996 Jul 30
3
NXP Semiconductors
Product specification
N-channel silicon field-effect transistors
DYNAMIC CHARACTERISTICS
Common source; T
amb
= 25
C;
unless otherwise specified.
SYMBOL
C
is
C
rs
C
os
g
is
g
os
y
fs
y
rs
y
os
f
gfs
F
PARAMETER
input capacitance
reverse transfer capacitance
output capacitance
input conductance
output conductance
forward transfer admittance
reverse transfer admittance
output admittance
cut-off frequency
noise figure
CONDITIONS
BF245A; BF245B; BF245C
MIN.
3
TYP. MAX.
4
1.1
1.6
250
40
6
1.4
25
700
1.5
6.5
UNIT
pF
pF
pF
S
S
mS
mS
mS
S
MHz
dB
V
DS
= 20 V; V
GS
=
1
V; f = 1 MHz
V
DS
= 20 V; V
GS
=
1
V; f = 1 MHz
V
DS
= 20 V; V
GS
=
1
V; f = 1 MHz
V
DS
= 15 V; V
GS
= 0; f = 200 MHz
V
DS
= 15 V; V
GS
= 0; f = 200 MHz
V
DS
= 15 V; V
GS
= 0; f = 1 kHz
V
DS
= 15 V; V
GS
= 0; f = 200 MHz
V
DS
= 15 V; V
GS
= 0; f = 200 MHz
V
DS
= 15 V; V
GS
= 0; f = 1 kHz
V
DS
= 15 V; V
GS
= 0; g
fs
= 0.7 of its
value at 1 kHz
V
DS
= 15 V; V
GS
= 0; f = 100 MHz;
R
G
= 1 k (common source);
input tuned to minimum noise
handbook, halfpage
−10
MGE785
handbook, halfpage
6
MGE789
IGSS
(nA)
−1
ID
(mA)
5
4
typ
−10
−1
3
2
−10
−2
1
−10
−3
0
50
100
Tj (°C)
150
0
−4
−2
VGS (V)
0
V
DS
= 0; V
GS
=
20
V.
V
DS
= 15 V; T
j
= 25
C.
Fig.2
Gate leakage current as a function of
junction temperature; typical values.
Fig.3
Transfer characteristics for BF245A;
typical values.
1996 Jul 30
4
NXP Semiconductors
Product specification
N-channel silicon field-effect transistors
BF245A; BF245B; BF245C
handbook, halfpage
6
MBH555
ID
(mA)
5
handbook, halfpage
15
MGE787
ID
(mA)
VGS = 0 V
4
10
3
−0.5
V
2
5
1
−1
V
−1.5
V
0
0
10
VDS (V)
20
0
−4
−2
VGS (V)
0
V
DS
= 15 V; T
j
= 25
C.
V
DS
= 15 V; T
j
= 25
C.
Fig.4
Output characteristics for BF245A;
typical values.
Fig.5
Transfer characteristics for BF245B;
typical values.
handbook, halfpage
15
MBH553
handbook, halfpage
30
MGE788
ID
(mA)
10
VGS = 0 V
ID
(mA)
20
−0.5
V
−1
V
5
10
−1.5
V
−2
V
−2.5
V
0
0
10
VDS (V)
20
0
−10
−5
VGS (V)
0
V
DS
= 15 V; T
j
= 25
C.
V
DS
= 15 V; T
j
= 25
C.
Fig.6
Output characteristics for BF245B;
typical values.
Fig.7
Transfer characteristics for BF245C;
typical values.
1996 Jul 30
5
