Three 16-bit sigma-delta ADCs — the metrology core
Its defining feature is the integrated three-channel 16-bit sigma-delta ADC block, which samples voltage and current channels simultaneously — the core measurement engine for utility-grade power calculations. The 8.4 MHz CPU clock is enough to run the metrology firmware loop and update the segment LCD display without external components. Program memory is 8 KB of Flash, with 256 x 8 bytes of RAM for runtime data and calibration coefficients. The part includes a built-in LCD driver, brown-out reset, POR, PWM, and watchdog timer, plus SPI and UART serial interfaces for communication with a host processor or sub-meter radio module.
Industrial temperature grade — outdoor enclosure ready
No commercial-grade derating needed for a meter sitting in a sun-baked cabinet or a sub-zero climate.
64-LQFP package — PCB layout notes
Housed in a 64-LQFP with a 10x10 mm body, surface-mount. The 14 general-purpose I/O pins are enough for tamper detection, relay drive, and status LEDs alongside the serial interface.