RF5373_1 Datasheet, PDF (6/14 Pages) RF Micro Devices – 1.8V TO 3.6V IEEE802.11b/g/n AND BLUETOOTH DRIVER/AMPLIFIER

RF5373
Theory of Operation
The RF5373 is a linear driver/amplifier that is designed for the 2.4GHz to 2.5GHz (IEEE802.11b/g and BT Class 1) band. Oper-
ating from a single 1.8V to 3.6V supply, the amplifier will easily be incorporated into WLAN designs with minimal external com-
ponents. The device is provided in a 2.2mmx2.2mmx0.6mm, 8-pin, QFN with a backside ground.
The RF5373 is a two-stage device with a nominal gain of 28dB to 29dB in the 2.4GHz to 2.5GHz ISM band. The RF5373 is
designed for multiple applications in the 2.4GHz to 2.5GHz band. The RF5373 requires only a single positive supply of 1.8V to
3.6V to operate to full specification. Power control is provided through one bias control input pin (V_REG) which can range from
1.6V nominal and 1.85V maximum. The PA circuit layout from the evaluation board should be copied as closely as possible,
particularly the ground layout and ground vias. Other configurations may also work, but the design process is much easier and
quicker if the layout is copied from the RF5373 evaluation board. Gerber files of our designs are available on request.
There are multiple applications where the RF5373 may be implemented, including IEEE802.11b/g and Bluetooth. Please
review the RF5373 schematics for the optimum layout for a specific band. In order to obtain the best performance for an
802.11g application where the PA will be pulsed at <99% duty cycle, R1 must be populated with a 56Ω resistor. For all other
applications where pulsing is not needed, R1 can be substituted with a 0Ω or a trace line.
An application schematic for 2.5GHz operation is included that has two additional components, one shunt inductor, and one
shunt capacitor, on the output for improved second harmonic rejection. This layout provides ~20dB rejection at 5GHz with a
minimal BOM count.
The RF5373 is not a difficult part to implement, but care in circuit layout and component selection is always advisable when
designing circuits to operate at 2.5GHz. The RF5373 evaluation board layout and schematic is also available using 0201 com-
ponents which will help shrink the six of the total area of the power amplifier and matching components on the intended
design.
Please contact RFMD Sales or Applications Engineering for additional data and guidance.
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Rev A6 DS070521