This application note shows how to re-use the CC1312PSIP FCC Modular Certification. The Federal Communications Commission (FCC) and Industry Canada (IC) certification covers the frequency band of 902MHz to 928MHz, but the CC1312PSIP can also operate in the 863MHz to 876MHz ISM band. To re-use the FCC and IC Certification, you must verify that you use the certified software PHYs and copy the hardware reference design as much as possible.
The software section covers all of the various PHYs that have been tested and the maximum power that can be transmitted for each particular PHY. Several PHYs are supported and the benefits of each particular PHY are covered.
The hardware section covers the recommended layouts for a two-layer design and a four-layer design. There are differences between certified antennas and non-certified antennas in the requirements for the reuse of the modular approval for use in Canada and the United States. The last section covers the recommended testing of the CC1312PSIP when assembled onto a main board.
This document walks through software and hardware related questions and how to re-use the FCC or IC certification that enables a quicker time-to-market.
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The SimpleLink™ CC1312PSIP [4.1] device is an RF certified System-in-Package (SiP) Sub-1GHz wireless module supporting Wi-SUN®, Wireless M-Bus, IEEE 802.15.4, IPv6-enabled smart objects (6LoWPAN), mioty, proprietary systems, including the TI 15.4-Stack. The CC1312PSIP microcontroller (MCU) is based on an Arm® Cortex® M4F main processor and optimized for low-power wireless communication and advanced sensing in grid infrastructure, building automation, retail automation, and medical applications.
The CC1312PSIP [4.1] has a low sleep current of 0.9μA with RTC and 80KB RAM retention. In addition to the main Cortex® M4F processor, the device also has an autonomous ultra-low power Sensor Controller CPU with fast wake-up capability. As an example, the sensor controller is capable of 1Hz ADC sampling at average 1μA system current.
The CC1312PSIP [4.1] has low soft error rate (SER) failure-in-time (FIT) for long operational lifetime. Always-on SRAM parity minimizes risk for corruption due to potential radiation events. Consistent with many customers 10 to 15 years or longer life cycle requirements, TI has a product life cycle policy with a commitment to product longevity and continuity of supply including dual sourcing of key components in the SIP.
The CC1312PSIP [4.1] device is part of the SimpleLink MCU platform, which consists of Wi-Fi™, Bluetooth® Low Energy, Thread, Zigbee™, Wi-SUN, Amazon Sidewalk, mioty, Sub-1GHz MCUs, and host MCUs. CC1312PSIP [4.1] is part of a portfolio that includes pin-compatible 2.4GHz SIPs for easy adaption of a wireless product to multiple communication standards. The common SimpleLink Low Power F2 SDK and SysConfig system configuration tool supports migration between devices in the portfolio. A comprehensive number of software stacks, application examples and SimpleLink Academy training sessions are included in the SDK.
By utilizing 3D assembly packaging with the SMD components placed on the CC1312PSIP [4.1] laminate and then placing the chip die directly above, the package volume is fully utilized. For the CC1312PSIP block diagram, see Figure 1-1. The RF filtering section has been was reduced to two singular components from 25 components by making two Integrated Passive Components (IPC). One IPC for the 14dBm Tx / Rx port and another for the 20dBm Tx port. This resulted in a final package size of 7 x 7mm with all components fully integrated.
With the traditional design shown in Figure 1-2, this has a PCB floor space of approximately 324mm (18 x 18mm); with the CC1312PSIP [4.1] this was reduced to just 49mm (7 x 7mm). That is an 85 % size reduction.
In addition, to the size reduction, fully certified PHYs and FCC / IC modular certification that enables the option just to re-use the certification. There are also new features such as SW-TCXO that provide TCXO accuracy.
The CC1312PSIPMOT is designed to operate in the 902MHz to 928MHz band where the FCC modular certification can be re-used. CC1312PSIPMOT can also be used for the 868MHz ISM band but this is not covered by the FCC modular certification. The maximum RF power transmitted is 20dBm but this is dependent on the PHY.
For ETSI operation within 863MHz to 876MHz ISM band. The output power does not exceed 14.0dBm between 863MHz to 870MHz. If greater than 14.0dBm is required, then the operating frequency has to be within 869.400MHz to 869.650MHz. Then 20dBm can be transmitted at 869.525MHz. 20dBm can also be used in the frequency region of 870MHz to 876MHz for certain countries in Europe but not all countries support this frequency region in the EU.
To evaluate the CC1312PSIP, there is a LaunchPad available LP-EM-CC1312PSIP [4.2] and this must be plugged into a LP-XDS110 or LP-XDS110ET. Figure 1-3 shows a LP-XDS110 on the left side and a LP-EM-CC1312PSIP [4.2] on the right side.
The FCC certification covers the frequency band of 902MHz to 928MHz but the CC1312PSIP [4.1] can also operate in the 863MHz to 876MHz ISM band.
The schematic of the radio section is shown in Figure 1-4. The components L1 and C1 are only required for operation at 20dBm at 869.525MHz or 870MHz to 876MHz, L1 must be 3.9nH and C1 must be 3.6pF.
If L1: 3.9nH and C1: 3.6pF are used at 902MHz to 928MHz, the output power is affected and the recommended output power settings in the SDK are invalid. Adding additional filtering on the RF output implies a Class 2 permissive change (C2PC); refer to section 3.3.2.2 for more information.
When matching the antenna, a low-pass or high-pass topology of match can be used. For the CC1312PSIP [4.1] we always recommend to use a low-pass antenna match as shown in Figure 1-4 by the antenna match components of Z10 and Z11.
There is no DC block in the CC1312PSIP [4.1] so component C57 acts as a DC block if required for the antenna section. In the LP-EM-CC1312PSIP [4.2] C57 is also used to switch to the integrated PCB antenna section. If we just required connection to the SMA, then the DC block is assembled at C56 instead and C57 is DNM.