Philips BLF278 - Application Information (Class-B); Class-B Operation Performance; Class-B Ruggedness

2003 Sep 19 6
Philips Semiconductors Product Specification
VHF push-pull power MOS transistor BLF278
Fig.8 Feedback capacitance as a function of
drain-source voltage; typical values per
section.
V
GS
= 0; f = 1 MHz.
handbook, halfpage
010 50
400
300
100
0
200
MGE620
20 30 40
C
rs
(pF)
V
DS
(V)
APPLICATION INFORMATION
Class-B operation
RF performance in CW operation in a common source push-pull test circuit. T
h
=25°C; R
th mb-h
= 0.15 K/W unless
otherwise specified. R
GS
=4Ω per section; optimum load impedance per section = 3.2 + j4.3 Ω (V
DS
= 50 V).
Ruggedness in class-B operation
The BLF278 is capable of withstanding a load mismatch corresponding to VSWR = 7:1 through all phases under the
following conditions: V
DS
= 50 V; f = 108 MHz at rated load power.
MODE OF OPERATION
f
(MHz)
V
DS
(V)
I
DQ
(A)
P
L
(W)
G
p
(dB)
η
D
(%)
CW, class-B 108 50 2 × 0.1 300 >20
typ. 22
>60
typ. 70
CW, class-C 108 50 V
GS
= 0 300 typ. 18 typ. 80