1.3.1.3.1 Abbreviations and Acronyms

Table 1-1. Abbreviations and Acronyms
Abbreviation Description
ADC

Analog-to-Digital Converter consisting of a PGA, a second-order Δ/Σ modulator and followed by an integrated third-order sinc3 decimation filter. A digitized conversion of an analog voltage, VADCin, is created using the following equation:

For best linearity, the product of ADC input voltage and the PGA gain must not exceed 0.5V, GPGA×VADCin≤0.5V, where GPGA for all voltage channels is fixed at 1.

AFE Analog Front End
API Application Programming Interface
Δ/Σ ADC Delta-Sigma Analog-to-Digital Converter, an over-sampled converter with noise shaping
CT Current Transformer sensor
DB Demo Board
DNP Do Not Populate
DSP Digital Signal Processor
GPIO General Purpose Input/Output
I_Ni Imputed neutral current
I_Nm Measured neutral current
I_Nmi Difference between the measured and imputed neutral currents
Kh Watt-hour meter constant for electro-mechanical meters, defines an amount of energy indicated by one (1) pulse generated by the meter and does not usually apply to solid-state meters
Kt Watt-hour meter test constant for solid-state meters, defines an amount of energy indicated by one (1) optical pulse generated by the meter and does not usually apply to electro-mechanical meters
LCD Liquid Crystal Display
MCU Microcontroller Unit
MSB Most Significant Bit, the left-most bit of a binary number
N The number of samples in any one measurement interval. This number may vary for each measurement interval
NA Not Available
OSR Over Sample Rate
PGA Programmable Gain Amplifier: The ADC channels associated with current measurement have an internal, selectable, programmable gain amplifier, which can provide an additional analog gain equal to GPGA. GPGA = [1, 2, 4 or 8]
SDK Software Development Kit
SoC System-on-Chip
TOU Time of Use
VP, VP-N

Voltage potential: VP is the voltage measured from node P to an explicit neutral reference voltage VP-M is the voltage measured from node P to node N, where a positive voltage is indicative of a voltage rise from node N to node P.

All phase diagrams are drawn as if mathematical vectors starting at 0° (3 o’clock) and rotating counter-clockwise for positive phase increases, with 90° being at 12 o’clock, 180° at 9 o’clock and 270° at 6 o’clock.