ADMV8420

Data Sheet

Rev. B | Page 12 of 14

EVALUATION PRINTED CIRCUIT BOARD (PCB)

All RF traces are routed on Layer 1 (primary side). The remaining

three layers are ground planes that provide a solid ground for RF

transmission lines, as shown in Figure 27. The top dielectric

material is Rogers 4350, which offers low loss performance. The

prepreg material in Layer 2 attaches the Isola 370HR core layer to

copper traces layers. Both the prepreg material and the Isola 370HR

core layer achieve the required board finish thickness.

NOMINAL

FINISHED

BOARD

THICKNESS 0.062"

±10%

PRIMARY SILKSCREEN

PRIMARY SOLDER MASK

PRIMARY SIDE

(LAYER 1)

L2_GND PLANE

(LAYER 2)

L3_GND PLANE

(LAYER 3)

SECONDARY SIDE (LAYER 4)

0.5oz Cu

ARLON OR ROGERS CORE 10MILS ±1MIL (CRITICAL)

0.5oz Cu

PREPREG AS REQUIRED

0.5oz Cu

370HR

0.5oz Cu

Figure 27. The Cross Sectional View of the ADMV8420-EVALZ PCB Layers

The circuit board in this application uses RF circuit design

techniques. Signal lines must have 50 Ω impedance. The package

ground leads and exposed pad must connect directly to the ground

plane (see Figure 27). A sufficient number of via holes connect the

top and bottom ground planes. The evaluation circuit board

shown in Figure 28 is available from Analog Devices, Inc. upon

request.

Figure 28. Evaluation PCB Layout, Top View