Data Sheet

ADRF5031

APPLICATIONS INFORMATION

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Rev. A | 11 of 12

The ADRF5031 has two power supply pins (VDD and VSS) and

two control pins (EN and CTRL). Figure 16 shows the external

components and connections for the supply pins. The VDD and

VSS pins are decoupled with a 100 pF capacitor. The pinout of the

ADRF5031 allows the placement of the decoupling capacitors close

to the device. No other external components are needed for bias

and operation, except for DC-blocking capacitors on the RFx and

RFC pins when the RF lines are biased at a voltage other than 0 V.

See Table 6 for further details.

Figure 16. 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 a 50 Ω char-

acteristic impedance on the PCB. Figure 17 shows the referenced

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

RO4003C dielectric material. A RF trace with a 14 mil width and 7

mil clearance is recommended for 1.5 mil finished copper thickness.

Figure 17. Example PCB Stack-Up

Figure 18 shows the routing of the RF traces, supply, and control

signals from the ADRF5031. The ground planes are connected with

densely filled through vias for optimal RF and thermal performance.

The primary thermal path for the ADRF5031 is the bottom side.

Figure 18. PCB Layout

Figure 19 shows the recommended layout from the RF pins of the

ADRF5031 to the 50 Ω CPWG on the referenced stack-up. PCB

pads are drawn 1:1 to the pads of the ADRF5031. 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 to the package edge and tapered to RF trace.

The paste mask is designed to match the pads of the ADRF5031

without any aperture reduction. The paste mask is divided into

multiple openings for the paddle.

Figure 19. Recommended RF Pin Transition

For alternate PCB stack-ups with different dielectric thickness and

RF trace design, contact Analog Devices Technical Support for

further recommendations.