RF5117_11 Datasheet, PDF (6/13 Pages) RF Micro Devices – LINEAR POWER AMPLIFIER

RF5117
The RF5117 can be used with an IEEE802.11g modulation with a few modifications. Pin 2 should not be connected to ground
and a 4.7k resistor should be placed on the V_REG1 line. This is done on the evaluation board by cutting the V_REG1 trace and
placing the resistor on the open line. All other components should not be modified and the IEEE802.11g schematic should be
followed as closely as possible.
Power sensing is implemented with the PWR SEN and PWR REF lines. The outputs of these pins are transistor collectors and
need to be pulled up to the supply through a resistor. PWR REF provides an output current proportional to the output stage bias
current, and PWR SEN provides an output current proportional to the total (RF and bias) current of the output stage. The pull-
up resistors convert these currents to voltages, and the voltage difference between these two pins is proportional to the RF
current. See the graph, “V_REF-V_SENSE versus P_OUT”, for the response of this signal. This difference signal can be fed to a power
control circuit elsewhere in the end product, or it can be processed at the PA with additional circuitry and used to adjust the
V_REG voltage(s) to implement automatic level control. Contact RFMD Sales or Applications Engineering for additional data and
guidance in using this feature.
The RF5117 has primarily been characterized with a voltage on V_REG1 and V_REG2 of 2.7V_DC. However, the RF5117 will operate
from a wide range of control voltages. If you prefer to use a control voltage that is significantly different than 2.7V_DC, contact
RFMD Sales or Applications Engineering for additional data and guidance.
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DS110617