This document provides the design guidelines of a 4-layer PCB board, for the CC31xx and CC32xx
SimpleLink™ Wi-Fi®family of devices. The CC31xx and CC32xx are easy to lay-out, QFN-packaged
devices. Optimize the board’s performance by following these suggestions during the board’s design. The
first section is a brief overview of the SimpleLink Wi-Fi family of devices. The second section focuses on
the PCB specification; the third section addresses components placement, and board layer information.
The last section, on layout guidelines, covers the board’s main sections such as RF, power, clock, digital
I/O, and the ground. Each section can be read independently.
In addition to this document, TI recommends verifying the schematic board design with the associated
schematic checklist.
1Trademarks
SimpleLink, Internet-on-a-chip, E2E are trademarks of Texas Instruments.
ARM, Cortex are registered trademarks of ARM Limited.
Wi-Fi is a registered trademark of Wi-Fi Alliance.
All other trademarks are the property of their respective owners.
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CC3100 and CC3200 SimpleLink™ Wi-Fi®and Internet of Things Solution
Layout Guidelines
Start the design with the industry’s first Internet-on-a-chip™. Created for the Internet of Things (IoT), the
SimpleLink Wi-Fi family has several variants. The CC3100 SimpleLink Wi-Fi and IoT solution dramatically
simplifies the implementation of Internet connectivity. This product integrates all protocols for Wi-Fi and
Internet, which greatly minimizes host microcontroller (MCU) software requirements. CC3200 device is a
wireless MCU that integrates a high-performance ARM®Cortex®-M4 MCU with the CC3100 network
processor subsystem, allowing customers to develop an entire application with a single IC. With on-chip
Wi-Fi, Internet, and robust security protocols, no prior Wi-Fi experience is needed for faster development.
SimpleLink Wi-Fi is a complete platform solution, including various tools and software, sample
applications, user and programming guides, reference designs, and the TI E2E™ support community. The
devices are available in an easy to lay-out QFN package. The layout for both devices are similar, with a
higher number of IOs routed for the CC3200.
3PCB Specification
3.1PCB Stack-Up
An example stack-up is shown in Figure 1, used for the construction of the CC3100BOOST Rev3.3-A. The
user can alter the layer stack-up based on their requirements, but the impedance of the 50-Ω lines should
be recalculated. Having the L1-L2 distance reduced helps improve the grounding and the RF decoupling.
TI recommends keeping the L1-L2 distance similar to the recommended value.
CC3100 and CC3200 SimpleLink™ Wi-Fi®and Internet of Things Solution
Layout Guidelines
5
PCB Specification
3.2PCB Design Rules
ParameterValueComments
Number of layers4
Thickness1.1 mm ±
Size of PCB2.0” x 1.7”
Solder maskRedCan be replaced with any color
DielectricFR4
SilkWhiteCan be replaced with any color
Surface finishENIG
Min track width6 milsMin track width can be reduced but cost would be higher
Min spacing6 milsMin spacing can be reduced but the cost would be higher
Mid drill diameter8 mils12-mil diameter drill is used on the Rev 3.3-A board
Copper thickness1 oz
Lead free / ROHSYes
Impedance controlYes50-Ω controlled impedance trace of 18-mils width on L1 w.r.t L2 (GND).
Impedance variation5%
www.ti.com
Table 1. PCB Design Rules
For greater thickness increase the distance between L2 and L3
10%
Air gap = 15 mils
Note: The above calculations are based on CPW-G (NOT microstrip).
3.3Layer Information
The 4-layer PCB is used with the configuration, as shown in Table 2.
Layer UsageNotes
1Signal + RFRF trace is a CPW on L1 w.r.t. L2 ground
2GNDReference plane for RF
3Power + signalThe power planes for the power amplifier (PA), analog blocks and the main input supply are routed on
4Power + signal
Table 2. 4 Layer PCB
this layer
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CC3100 and CC3200 SimpleLink™ Wi-Fi®and Internet of Things Solution
Layout Guidelines
The complete layout package is available for download on the TI website at http://www.ti.com/tool/cc3200-
launchxl-rd and http://www.ti.com/tool/cc3100boost-rd. TI recommends that the customers copy the exact
layout of the engine area to ensure optimum performance as measured on the CC3x00 reference boards.
4.1Placement of Components
The components placement on the CC3100 BoosterPack is provided in Figure 2. This placement provides
optimum performance of the device. Great care must be taken for the power inductors components to
ensure reduced emissions and optimum EVM and mask performance. The power inductors should be
placed close to the device, and the power traces should be minimized. The CC3x00 device is sensitive to
the layout of the DC-DC converter, which can impact the performance of the device. For the main
inductors at the analog, power amplifier, and digital DC-DC output, see Table 3.