RF2451
Pin
1
2
3
4
5
Function
RF OUT
ISET
VCC
ENABLE
IPSET
Description
RF output pin. Bias for the LNA is provided through this pin, hence it
should be connected to VCC through an inductor.
This pin sets the current for the device. A resistor to ground of 1kΩ pro-
vides a current of 17.5mA. The condition for optimal IP3 is to use the
internal current setting option and leave this pin open (no connect).
Power supply for the bias circuits.
Power down control. This is a CMOS input. When this pin is CMOS
“high” the device is enabled. When the level is CMOS “low” the device
is shut off and a controlled attenuator is turned on.
This pin selects the internal current setting when CMOS level “low”, and
the external current setting when this pin is CMOS level “high”. The cur-
rent is set to 2.8mA using the internal current setting, and can be up to
20mA using the external current setting.
Ground connection for the bias circuits.
Ground connection for the LNA. Keep traces physically short and con-
nect immediately to ground plane for best performance.
RF input pin. This pin is not internally DC blocked and requires an
external blocking capacitor.
Interface Schematic
D
R
E
F2
S
37
IG
1
N
S
8
RF IN
N
S
ee
O
T
U
Rev A8 000822
pg
r
FO
ad
R
e
d
N
P
ro
EW
d
uc
t
4-249
GENERAL PURPOSE
AMPLIFIERS
6
7
GND2
GND1
4
RFMD [ RF MICRO DEVICES ]
