Data Sheet

ADRF5080

APPLICATIONS INFORMATION

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Rev. 0 | 14 of 15

The ADRF5080 has two power supply pins (VDD and VSS) and

five digital control pins (LS, EN, V1, V2, and V3). Figure 27 shows

the external components and connections for the supply and control

pins. Supply and control pins are decoupled with a 10 pF or 100

pF multilayer ceramic capacitor. The device pinout allows the place-

ment of the decoupling capacitors close to the device. No other

external components are needed for bias and operation, except

DC blocking capacitors on the RFx pins when the RF lines are

biased at a voltage different than 0 V. Refer to Pin Configuration

and Function Descriptions section for further details.

Figure 27. Recommended Schematic

RECOMMENDATIONS FOR PCB DESIGN

The RF ports are matched to 50 Ω internally and the pinout is

designed to mate a coplanar waveguide (CPWG) with 50 Ω charac-

teristic impedance on the PCB. Figure 28 shows the referenced

CPWG RF trace design for an RF substrate with 8 mil thick Rogers

RO4003 dielectric material. The RF trace with a 14 mil width and

a 7 mil clearance is recommended for 2.8 mil finished copper

thickness.

Figure 28. Example PCB Stackup

Figure 29 shows the routing of the RF traces, supply, and control

signals from the device. The ground planes are connected with as

many filled through vias as allowed for optimal RF and thermal

performance. The primary thermal path for the device is the bottom

side.

Figure 29. PCB Routings

Figure 30 shows the recommended layout from the device RFx

pins to the 50 Ω CPWG on the referenced stackup. PCB pads are

drawn 1:1 to device pads. The ground pads are drawn solder mask

defined, and the signal pads are drawn as pad defined. The RF

trace from the PCB pad is extended with the same width by 2 mils

and tapered to an RF trace with 45° angle. The paste mask is

also designed to match the pad without any aperture reduction. The

paste is divided into multiple openings for the paddle.

Figure 30. Recommended RFx Pin Transitions

For alternate PCB stackups with different dielectric thickness and

CPWG design, contact Analog Devices, Inc., Technical Support

Request for further recommendations.