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RF5722

DS110619

7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical

support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.

Theory of Operation and Application Information

The RF5722 is a two-stage power amplifier (PA) with a minimum gain of 24dB minimum gain in the 2.4GHz to 2.5GHz ISM

band. The RF5722 has integrated input, interstage and output matching components thus allowing minimal bill of material

(BOM) parts count in end applications. The RF5722 is designed primarily for IEEE802.11b/g/n WiFi applications where the

available supply voltage and current are limited. This amplifier will operate to (and below) the lowest expected voltage made

available by a typical PCMCIA slot in a laptop PC, and will maintain required linearity at decreased supply voltages.

The RF5722 requires only a single positive supply of 3.3V nominal (or greater) to operate to full specifications. Power control is

For best results, the PA circuit layout from the evaluation board should be copied as closely as possible, particularly the ground

layout and ground vias. Pin 4 must be left as a no-connect on the PCB in order for the PA to work properly. Other configurations

may also work, but the design process is much easier and quicker if the layout is copied from the RF5722 evaluation board.

Gerber files of RFMD PCBA designs can be provided on request. The RF5722 is a very easy part to implement, but care in cir-

cuit layout and component selection is always advisable when designing circuits to operate at 2.5GHz. The RF5722 evaluation

board layout and schematic are available using 0201 (US) size components which will help shrink the overall size of the total

area of the PA and components of the intended design. Please contact RFMD Sales or Application Engineering for additional

data and guidance.

For best performance, it is important to duplicate (as closely as possible) the layout of the evaluation board. The RF5722 has

neering for additional data and guidance.

QFN8 Package Area versus Other Small Form Factor Package Areas

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 rejecetion at 5GHz with a

minimal BOM count.

Package Type

Length (mm)

Width (mm)

SOT 23-6

3.1

3.0

9.30

4.46

QFN12

3.0

3.0

9.00

4.16

SOT 23-5

2.9

2.8

8.12

3.28

QFN8

2.2

2.2

4.84

0.00