I have often heard people use the phrase “...talking loud and sayin’ nothing.” Usually, this is a sarcastic referral indicating that the substance of the conversation was a bit less than revolutionary. But if taken literally, it could indicate that the listener was unable to interpret the speaker’s meaning, which entails a lack of communication. In communications systems, this is more commonly referred to as “noise.”
The proliferation of internet of things (IoT) architectures, which require various systems capable of communicating with each other, makes noise control even more critical than for other communications systems. The responsibility of devising and enforcing solutions to minimize noise and interference among devices comprising these systems primarily falls under the umbrella of the Federal Communications Commission (FCC). Let’s explore the FCC regulations applicable to IoT systems and establish guidelines for manufacturing IoT devices that adhere to those requirements.
Which FCC Regulations are Applicable to IoT Systems?
Much of the effort expended in designing PCBs involves minimizing or eliminating noise, which can be defined as any signal that is not desirable at the point it is detected or received. Excessive noise on your board can result in reduced functionality or erratic performance due to loss of signal integrity. Either case is unacceptable, but greater concerns are the effect on nearby systems and potential adverse health impacts. The minimization or prevention of these hazards drives several efforts of the FCC. In response, there are a number of methods that are used by the agency including allocating radio frequency (RF) spectrum positions to certain classes of products, placing electromagnetic radiation limitations on devices and requiring testing and certification for certain components and systems. The complete set of FCC rules can be found in Title 47 of the Code of Federal Regulations (CFR).
Most likely, if your electronic device, PCB or system communicates wirelessly or contains a microprocessor, it is considered an RF device that is subject to FCC equipment authorization. An RF device is defined as having the capability to emit energy in the 9 kHz to 3000 GHz frequency range and may be classified into one or more of the categories listed below:
IoT RF DEVICE CATEGORIES AND FCC REGULATIONS
|Common Devices||Description||FCC Category||Applicable FCC Title 47 Regulation(s)|
|AC and DC motors, light switches (mechanical), basic electric power tools||Devices not designed for energy radiation||Incidental Radiator||Part 15 Subpart A|
|Same devices as for Incidental Radiator with digital control||Devices that use digital logic and send RF internally or use cables for external signal transmission||Unintentional Radiator||Part 15 Subparts B and G|
|Wi-Fi transmitters, Bluetooth or Bluetooth low energy (BLE) devices, remote control units, wireless garage door openers, wireless alarm systems||Devices that intentionally generate and emit energy wirelessly (radiation or induction)||Intentional Radiator||Part 15 Subparts C-F and H|
|Halogen ballasts, fluorescent lighting, microwave ovens, arc welders, medical diathermy machines||Devices designed to provide energy for other than telecommunications purposes||Industrial, Scientific and Medical Equipment||Part 18|
|Cell phones, Smartphones, base stations, mobile transmitters, aviation and marine radios, low power TV transmitters||Products that use the licensed frequency spectrum||Equipment operating in Licensed Radio Services||Based upon Frequency Allocation of Service|
If thus classified, your device will need to be tested to ensure compliance with applicable FCC regulations unless it qualifies for an electromagnetic interference (EMI) testing exemption. As an example, digital devices that operate below 1.705MHz and do not connect to the AC grid are products that are exempt.
Guidelines for Manufacturing IoT Devices Meeting FCC Regulations
Electronic systems are utilized in all layers of the typical IoT system architecture – device, edge and cloud – which means that if you design boards for IoT implementation, you will need to comply with FCC regulations. In order to ensure compliance, it is recommended that you partner with a CM early in the design and development process and follow the guidelines below.
- Utilize FCC pre-certified IoT RF modules, whenever possible.
Using components or modules that have already been tested and FCC certified can result in significant time and cost savings as additional testing is not required. However, testing may be necessary if you make modifications.
- Determine the FCC rules that apply to your device.
This may include technical and administrative rules. The table above can be used as a guide for technical rules and the administrative rules can generally be found under Part 2 subpart j of Title 47.
- Institute design for EMC compliance techniques and elements, such as filters and shielding to minimize noise and interference into your design.
As FCC regulations compliance can add time and cost to the development of your PCB you need to institute steps to optimize the manufacture of your boards.
- Determine which equipment authorization procedure is required for your product.
- Institute device testing by your CM to ascertain your board’s adherence to the FCC regulation(s), if possible.
It may be possible for your CM to test your board. For example, if SDoC compliance is required, your CM may be able to help. If this is the case, you can save development time and lower costs; however, specific measurements are required and must be implemented.
- If required, perform compliance testing at an authorized laboratory.
Certification mandates that you use an FCC-recognized accredited testing laboratory.
- Label your product appropriately and maintain records of all compliance testing and results.
Be sure to follow labeling guidelines as set forth by the FCC.
Following the above guidelines will help you get your IoT device approved.
When designing PCBs for IoT architectures, your choice of CM can result in smooth and efficient board manufacturing with quick compliance versus extensive back and forth, potential redesigns and a painfully long approval process.
Tempo Automation is the industry leader in fast, precise and high-quality prototype PCB manufacturing. At Tempo, we will work with you from the beginning of design to assist you in meeting any regulatory and standard requirements for your PCB design.
|Tempo‘s Custom PCB Manufacturing Service
And to help you get started on the best path, we furnish information for your DFM and enable you to easily view and download DRC files. If you’re an Altium user, you can simply add these files to your PCB design software.
If you are ready to have your design manufactured, try our quote tool to upload your CAD and BOM files. If you want more information on FCC regulations or how to implement PCB design and development guidelines to ensure that your boards meet FCC requirements, contact us.
1 Currently, frequency allocation is divided between the FCC (non-governmental use) and the National Telecommunications and Information Administration (NTIA).