RF2312
Pin
1
Function
RF IN
Description
RF input pin. This pin is NOT internally DC-blocked. A DC-blocking
capacitor, suitable for the frequency of operation, should be used in all
applications. The device has internal feedback, and not using a DC-
blocking capacitor will disable the temperature compensation.The bias
of the device can be controlled by this pin. Adding an optional 1kΩ
resistor to ground on this pin reduces the bias level, which may be com-
pensated for by a higher supply voltage to maintain the appropriate
bias level. The net effect of this is an increased output power capability,
as well as higher linearity for signals with high crest factors. DC-cou-
pling of the input is not allowed, because this will override the internal
feedback loop and cause temperature instability.
Ground connection. For best performance, keep traces physically short
and connect immediately to ground plane. Each ground pin should
have a via to the ground plane.
Same as pin 2.
Same as pin 2.
Same as pin 2.
Same as pin 2.
Same as pin 2.
RF output and bias pin. Because DC is present on this pin, a DC-block-
ing capacitor, suitable for the frequency of operation, should be used in
most applications. For biasing, an RF choke in series with a resistor is
needed. The value for the resistor R
C
is 30Ω (0.5W) for V
CC
=9V and
21Ω for V
CC
=8V. The DC voltage on this pin is typically 6.0V with a
current of 100mA. In lower power applications the value of R
C
can be
increased to lower the current and V
D
on this pin.
RF OUT
Interface Schematic
2
3
4
5
6
7
8
GND
GND
GND
GND
GND
GND
RF OUT
RF IN
Rev C6 051025
3-5
RFMD [ RF MICRO DEVICES ]
