RF5187 Datasheet, PDF (3/6 Pages) RF Micro Devices – LOW POWER LINEAR AMPLIFIER

Preliminary
RF5187
Pin Function Description
Interface Schematic
1
RF IN
RF input. This input is DC-coupled, so an external blocking capacitor is
required if this pin is connected to a DC path. An optimum match to
50Ω is obtained by providing an external series capacitor of 2.4pF and
then a shunt capacitor of 2.4pF. Those values are typical for 2140MHz;
other values may be required for other frequencies.
2
RF IN
Same as pin 1.
3
PC
Power control pin. For obtaining maximum performance, the voltage on
2
this pin can be used to set correct bias level. In a typical application this
is implemented by a feedback loop. The feedback can be based on the
actual supply current of the device (i.e. maintaining a fixed current
level), or it can be based on the RF output power level to maintain a
fixed RF power level (Automatic Level Control loop). A voltage of 0.5V
or lower brings the part into power down state.
4
VCC
Power supply pin for the bias circuits. External low frequency bypass
capacitors should be connected if no other low frequency decoupling is
nearby.
5
RF OUT ^{RF output and bias for the output stage. The power supply for the out-}
put transistor needs to be supplied to this pin. This can be done
through a quarter-wavelength microstrip line that is RF-grounded at the
other end, or through an RF inductor that supports the required DC cur-
rents. Optimum load impedance is achieved by providing a shunt
capacitor of 1.8pF and a series capacitor of 3.3pF. Those values are
typical for 2140MHz; other values may be required for other frequen-
cies. Since there are several output pins available (which are internally
connected), one pin can be used for connecting the bias, another for
connecting a (third) harmonic trap filter, and the other pins for the RF
output.
6
RF OUT ^{Same as pin 5.}
7
RF OUT ^{Same as pin 5.}
8
RF OUT ^{Same as pin 5.}
Pkg
Base
GND
Ground connection. The backside of the package should be connected
to the ground plane through a short path (i.e., vias under the device
may be required).
Rev A1 011016
2-75