The Kinetis M Series One-Phase Power Meter Reference Design from NXP is designed for the measurement and registration of active and reactive energy in single-phase two-wire networks for direct connection.
With the increasing global demand for energy, accurate and cost-effective energy metering solutions have become crucial for utility providers, particularly in the residential market. To tackle this problem, NXP has released a reference design for a single-phase power meter. The Kinetis M series one-phase power meter reference design offers an accurate, cost-effective, and feature-rich solution for energy metering in single-phase two-wire networks. Its high-performance analog front end, advanced functionality, and robust components ensure precise energy measurement, compliance with international standards, and efficient operation.
The Kinetis M Series One-Phase Power Meter Reference Design from NXP offers a high-performance analog front end (AFE) coupled with an embedded programmable gain amplifier (PGA). This combination significantly enhances the accuracy of energy measurement while providing a cost-effective shunt sensing circuit implementation and bill of materials (BOM). The single-phase meter reference design is specifically designed for the measurement and registration of active and reactive energy in single-phase two-wire networks for direct connection. The reference design features a certification according to European EN50470-1, EN50470-3 (class B and C), as well as IEC 62053-21 and IEC 62052-11 international standards for electronic meters of active energy classes 2 and 1. This ensures its compliance with the strict accuracy requirements of energy metering applications.
The reference design is based on the Kinetis KM34Z128 MCU, which features an ARM Cortex-M0+ core operating at up to 50 MHz. It offers a high-resolution analog front end with four 24-bit sigma-delta ADCs, delivering exceptional signal-to-noise ratio (SNR). The MCU includes built-in voltage references (VREF) and a programmable gain amplifier (PGA) with low drift over temperature, ensuring accurate and stable energy measurement. The reference design also incorporates advanced features to enhance functionality and flexibility. An integrated switched-mode power supply (buck converter) ensures efficient operation of the meter electronics while providing sufficient power for optional modules such as non-volatile memory (NVM) for data logging and firmware storage. Additionally, a low-power, 3-axis Xtrinsic tilt sensor is included for electronic tamper detection, allowing the meter to detect unexpected changes in its coordinates and protect against physical tampering.
The reference design also integrates a battery which offers power backup to the MCU in case of power outages. This ensures continuous operation and activation of the meter when required, such as when a user button is pressed or a tamper event occurs. The design also incorporates tamper switches to protect the main and terminal covers, further enhancing security. Additionally, an RF communication module enables advanced meter reading (AMR) and remote monitoring, facilitating efficient management of energy consumption. The Kinetis M Series One-Phase Power Meter Reference Design is accompanied by comprehensive software support. Multiple advanced metering algorithms, such as filter-based and FFT-based methods, are provided to facilitate accurate energy measurement. The design incorporates the MQX real-time operating system and a comprehensive peripheral library, simplifying development and integration into metering applications.
This reference design has been tested by NXP. It comes with required design resources such as sample code, schematics, comprehensive documentation, etc. You can find additional data about the reference design on the company’s website. To read more about this reference design click here.