BL0942

BL0942 is a single-phase energy metering IC from Shanghai Belling in TSSOP-14, with an SOP-8 variant also offered — a calibration-free metering front end for smart plugs, sub-meters and appliance energy measurement. It runs from a single 3.3 V supply, measures current from 10 mA to 35 A across a 1 mΩ shunt resistor, and holds factory gain error below 1% with no calibration step on the production line, using its internal 1.218 V reference source and an internal clock of roughly 4 MHz. SPI and UART interfaces let a low-cost MCU read the measurements, and typical consumption is about 10 mW. Selection advice: the calibration-free behaviour is the cost driver — it removes the per-unit calibration station that shunt-based meters usually need — so confirm your shunt value and current range against the BL0942 datasheet (V1.1) and fix the TSSOP-14 or SOP-8 package before layout, because the two footprints are not interchangeable. Parameters verified against Shanghai Belling documentation.