A single-phase power meter requires the electrical power calculation that measures accurate power consumption from current, voltage and clock information, and the clock function that operates on a battery when there is a power outage. The power meter must have stable operation during a specified period of time. Further, the smart power meter needs to meet the security requirements of the Device Language Message Specification (DLMS) international standard.

Renesas offers microcontrollers (MCUs) for single-phase power meters that enable accurate power metrology and highly-integrated reliability.

The RL78/I1B microcontroller realizes the accurate metrology via a 24-bit Delta-Sigma A/D converter integrated with a phase adjustment circuit and high-pass filter function, and by a real-time clock with clock error correction function. The RL78/I1B is also equipped with LCD controller/driver functions and a high-speed on-chip oscillator with clock frequency correction function, making it ideal for basic single-phase power meters.

In addition, the RL78/I1C microcontroller is equipped with an encryption/decryption processing hardware engine that supports AES encryption GCM mode which is a security requirement for the DLMS standard, making it ideal for smart power meters that require communication functions.

Single-phase Power Meter