ACS37800: Highly Isolated, Programmable AC and DC Power Monitoring IC

The ACS37800 power monitoring IC greatly simplifies the addition of power monitoring to any AC and DC powered device. By making use of Allegro’s Hall-effect-based, galvanically isolated integrated current sensor technology, reinforced isolation can be achieved without extra board space. The sensor can also be powered from the same supply as the MCU, eliminating the need for multiple power supplies and digital isolation ICs. Furthermore, the isolated current measurement is done by detecting the magnetic field from the integrated conductor, eliminating the need for external sense resistors, current transformers, or Rogowski coils, resulting in a highly integrated power monitoring solution reducing PCB footprint.

Two Hall plates are used for this measurement to deferentially sense the field, thus eliminating errors due to stray magnetic fields. Multiple parameters like averaging and zero crossing time or channels, and fault levels are user-programmable. The sensor features all key power measurements, which can be read out through I2C or SPI, as well as dedicated pins for voltage or current zero crossing (suitable for light-dimming applications) and fast overcurrent fault (for short-circuit detection). These two pins can also be configured to flag a VRMS under/overvoltage.

The ACS37800 is provided in a small, low-profile, surface-mount SOIC16 wide-body package. The ACS37800 is lead (Pb) free, and is fully calibrated prior to shipment from the factory. It can be configured easily thanks to a GUI software to be downloaded. Further customer calibration in application can improve accuracy.

TYPICAL APPLICATIONS

• IoT devices wanting to track power consumption (Smart Receptacle)
• Smart Lighting
• Server and Telecom power
• Portable solar/energy systems used in disaster recovery
• Asymmetric AC waveform applications

• User-programmable VRMS under/overvoltage pin
• Dedicated voltage or current zero crossing pin
• User-programmable overcurrent fault (OCF) 
• I2C or SPI communication
• Programmable averaging on 2 out of the 3 outputs: Voltage, Current or Power