This reference design implements Class 0.5 single-phase energy measurement using standalone multi-channel analog-to-digital converters (ADC) to sample a shunt current sensor. With the combination of the shunt sensor and a compact magnetically immune power supply, the design provides protection against magnetic tampering attacks. The design also provides the capability to detect potential tampering from neutral line disconnection. The combination of a high-performance ARM Cortex-M4 MCU to execute the metrology calculations and 8-kHz sampling rate allows the addition of power quality functions, such as individual harmonic analysis.
Features
- Class 0.5 single-phase metrology tested across 50-mA to 90-A input range
- Calculated parameters include active and reactive energy and power, RMS line current, RMS neutral current, RMS voltage, power factor, and line frequency
- Detects potential tamper attacks with low-power current detection mode
- Compact non-magnetic power supply using active clamped capacitor-drop regulator with power good indication and supply failure alerts
- RS-485 and RS-232 interfaces with 5kV RMS isolation
- Complete, tested reference design with hardware files and design guide