Power monitoring IC simplifies automation and optimises energy efficiency
Power, voltage and current monitoring are integrated with reinforced isolation in the ACS37800 IC from Allegro.
The Hall-effect power monitoring IC is intended for single-phase AC and DC solutions in a small PCB footprint. It is also, says Allegro, an industry-first in that 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 1480Vpk in a small SOIC16W package. These characteristics reduce the bill of materials size, cost and complexity.
The power monitoring chip is “a gamechanger for IoT devices, smart lighting, data centres, and telecomms applications, in particular,” says Shaun Milano, business unit director for current sensors at Allegro. He lists improvements on earlier integrated ICs, such as the added ability to measure voltage, current and power in AC as well as DC at the same time. Adding reinforced isolation means customers can eliminate many expensive components on their PCBs, he adds. For example, the integrated 517Vrms reinforced isolation enables current sensing without expensive opto-isolators, Rogowski coils, oversized current transformers, isolated operational amplifiers, or shunt resistors, says Allegro.
Thanks to its onboard regulator, the ACS37800 can be powered from the same voltage supply as the system microprocessor (5.0 or 3.3V). In addition, the IC 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. It is able to average these parameters with many instantaneous measurements over a one minute period, avoiding inaccuracies when waveforms are asymmetric, says Allegro. These features reduce the reliance on microcontroller unit resources for critical calculations.
The ACS37800 allows devices to track power consumption and optimise energy use by detecting reduced power efficiency for predictive maintenance. It is suitable for use in motor control, building automation, and energy-saving/energy conscious industrial applications.
The IC is offered in an efficient SOIC16 footprint.
The device allows designers to choose from a factory-programmed I2C interface or SPI, depending on whether the user prefers low noise or multiple addressing. In I2C mode, it provides zero-crossing detection pinout, making LED dimming control easy. Users can also programme thresholds for under- or over-voltage, current or voltage gain and offset, and over-current trip point via EEPROM, allowing them to optimise the system from ±30 to ±180A and from –40 to 125 degrees C.
Allegro’s factory programming of sensitivity and offset with vast user programmability allows designers to balance between time-to-market and customisation applications, such as smart lighting, smart appliances and smart plugs, industrial motor control as well as server and telecomms power supplies.
