A power-monitoring chip from New Hampshire-based Allegro MicroSystems is targeting IoT devices and smart lighting products.

The ACS37800 IC integrates power, voltage and current monitoring with reinforced isolation, simplifying industrial and home automation applications seeking to reduce board space and optimise energy efficiency.

The Hall-effect power monitoring IC is for single-phase AC and DC use in a small PCB footprint. It is an integrated power-monitoring chip that allows simultaneous measurement of power, voltage and current for AC and DC signals with an isolation rating of up to 1480V peak in a SOIC16W package.

“Our newest power-monitoring chip is a game changer for IoT devices, smart lighting, data centres and telecom applications, in particular,” said Shaun Milano, business unit director for current sensors at Allegro. “We’ve improved on our first-generation integrated solution by adding the ability to measure voltage, current and power in AC as well as DC at the same time, And with reinforced isolation, our customers can eliminate many expensive components on their PCBs. The ACS37800 dramatically simplifies measuring power in a unique single chip.”

It helps devices track power consumption and optimise energy use by detecting reduced power efficiency for predictive maintenance. This makes it suitable for motor control, building automation and various green industrial applications.

Offered in a SOIC16 footprint, it reduces PCB size and bill of materials cost and complexity by eliminating the need for many components that other products require in similar conditions. For example, the integrated 517V RMS reinforced isolation enables current sensing without expensive optoisolators, Rogowski coils, oversized current transformers, isolated operational amplifiers or shunt resistors.

Thanks to its on-board regulator, it can be powered from the same voltage supply as the system microprocessor, either 5 or 3.3V.

The device simplifies common power triangle measurements by calculating parameters such as the active, reactive and apparent power as well as instantaneous and RMS values of the current, voltage or power. Furthermore, it can average these parameters with many instantaneous measurements over a one-minute period, avoiding inaccuracies when waveforms are asymmetric. These features reduce the reliance on microcontroller resources for critical calculations.

Users can programme the device to fit various applications. Designers can choose from a factory-programmed I²C or SPI interface, depending on whether the user prefers low noise or multiple addressing. In I²C mode, it provides zero-crossing detection pin-out, making LED dimming control easier.

Users can also programme thresholds for under and overvoltage, current and voltage gain, and offset and overcurrent trip point via EEPROM, allowing them to optimise their system from ±30 to ±180A and from -40 to +125˚C.

Combining Allegro’s factory programming of sensitivity and offset with user programmability allows designers to balance between time-to-market and customisation in the increasingly competitive energy-efficient applications, such as smart lighting, smart appliances, smart plugs, industrial motor control, and server and telecom power supplies.