Datasheet

NXP Semiconductors Product specification
Dual-gate MOS-FETs BF908; BF908R
THERMAL CHARACTERISTICS
Note
1. Device mounted on a printed-circuit board.
STATIC CHARACTERISTICS
T
j
=25°C; unless otherwise specified.
DYNAMIC CHARACTERISTICS
Common source; T
amb
=25°C; V
DS
=8V; V
G2-S
=4V; I
D
= 15 mA; unless otherwise specified.
SYMBOL PARAMETER CONDITIONS VALUE UNIT
R
th j-a
thermal resistance from junction to ambient note 1
BF908 500 K/W
BF908R 550 K/W
SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT
±V
(BR)G1-SS
gate 1-source breakdown voltage V
G2-S
=V
DS
= 0; I
G1-S
=10mA 8 − 20 V
±V
(BR)G2-SS
gate 2-source breakdown voltage V
G1-S
=V
DS
= 0; I
G2-S
=10mA 8 − 20 V
−V
(P)G1-S
gate 1-source cut-off voltage V
G2-S
=4V; V
DS
=8V; I
D
=20µA −−2V
−V
(P)G2-S
gate 2-source cut-off voltage V
G1-S
=4V; V
DS
=8V; I
D
=20µA −−1.5 V
I
DSS
drain-source current V
G2-S
=4V; V
DS
=8V; V
G1-S
=03 1527mA
±I
G1-SS
gate 1 cut-off current V
G2-S
=V
DS
= 0; V
G1-S
=5V −−50 nA
±I
G2-SS
gate 2 cut-off current V
G1-S
=V
DS
= 0; V
G2-S
=5V −−50 nA
SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT
y
fs
 forward transfer admittance pulsed; T
j
=25°C; f = 1 MHz 36 43 50 mS
C
ig1-s
input capacitance at gate 1 f = 1 MHz 2.4 3.1 4 pF
C
ig2-s
input capacitance at gate 2 f = 1 MHz 1.2 1.8 2.5 pF
C
os
output capacitance f = 1 MHz 1.2 1.7 2.2 pF
C
rs
reverse transfer capacitance f = 1 MHz 20 30 45 fF
F noise figure f = 200 MHz; G
S
= 2 mS; B
S
=B
Sopt
− 0.6 1.2 dB
f = 800 MHz; G
S
=G
Sopt
; B
S
=B
Sopt
− 1.5 2.5 dB
Rev. 03 - 14 November 2007
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