INTEGRATED POWER MONITORING THE FUTURE OF SMARTER HOMESACS37800: Single Phase, Isolated, AC/DC Power Monitoring IC
Smart lighting. Appliances. Blinds. Doors and gates.
Growth in the home automation industry has beenturbocharged in recent years as consumers adopt newtechnologies—and continually expect more intelligenceand energy efficiency from their smart homes. But that
intelligence and efficiency require accurate and safe
electrical monitoring of our most power-hungry devices,
including the voltage, current, and power they use.
For the first time, it’s possible with a single, space-saving
IC—Allegro’s ACS37800.
The ACS37800 is an integrated, single-phase AC and DC
power monitoring chip that simultaneously monitors power,voltage, and current up to 180A with a reinforced isolation
rating of up to 517 Vrms. This IC allows smart devices toeasily track power consumption and optimize energy use
and detect reduced motor efficiency to allow for predictive
maintenance.
Alternative power monitoring solutions with high isolationlevels similar to the ACS37800 are typically expensive andrequire significant board space. In a tiny SOIC16 package,
this IC reduces both PCB cost and size by eliminating theneed for components like current sense resistors,opto-isolators, dual-output supplies, regulators, andcomparators.

The ACS37800 provides both instantaneous and RMS
measurements for the current, voltage, and power whichsimplifies common power measurements like the active,reactive, and apparent power by reducing the processing
cycles required from the MCU and time to market.
Thanks to impressive flexibility and configurability, users canprogram the ACS37800 to fit unique application needs.
The device allows designers to choose from an I2C or SPI
interface, and with zero crossing detection (ZCD) in I2C
mode, LED dimming control is easy. Users can also program
thresholds for over/under-voltage, current/voltage gain andoffset, as well as the overcurrent trip points.
Thanks to its magnetic and non-contact current sensing, as
well as a low 0.85mΩ internal conductor resistancevalue, Allegro’s ACS37800 offers its customers
the capability to easily monitor andoptimize the energy efficiency ofpower supplies, lighting,and motor control
sub-systems inconnected building
automation solutions
while simplifying thesystem design.

Features and Benefits• 0 to 90A current range (up to 180 with lower accuracy)• Precise current, voltage and power measurementswith capability to average over a full period• Wide temperature range: -40 to +125°C• Current or Voltage Zero Crossing output particularly
useful for light dimming and motor control• Low primary conductor: 0.85mΩ

• 3.3 and 5V• High isolation: 517Vrms reinforced isolation, 1047Vrms
working voltage and 4.8kVrms dielectric• Supports I2C and SPI interfaces• Bandwidth: 1kHz

• Overcurrent fault output pin for fast response time (5 μs)

Your smart home power monitoring solutionApplications• IoT Building Automation(smart appliances, smart plugand receptacles, smart lighting)• Motor Control• Power Supplies(data center servers and telecom)

ACS37800 Selection GuideAllowing 5 and 3.3V options, choosing between I2C and SPI, and multiple different sensitivity options.
Part Number

VCC (NOM)(V)

IPR(A)ACS37800KMABTR-015B5-SPI5+-15

ACS37800KMABTR-030B3-SPI

3.3+-30

ACS37800KMABTR-030B3-I2C

3.3+-30

ACS37800KMABTR-090B3-I2C

3.3+-90

CommunicationProtocol

TA (°C)

Packaging-40 to +125

Tape and Reel,
1,000 pieces per reel,
3,000 pieces per box

SPI

I2C

Makes LED Dimming Control Easy
LED dimming requires AC line zero crossing detection (ZCD) to synchronize control circuitry. ZCD is used to prevent lamp
flickering when dimming.

Voltage Zero
Crossing Modes

ALLEGROMICRO.COM

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