ACS709 Current Sensor Carrier -75 to +75A [145]

This board is a simple carrier of Allegro�s �75A ACS709 Hall effect-based linear current sensor with overcurrent fault output which offers a low-resistance (~1.1 m?) current path and electrical isolation up to 2.1 kV RMS. The sensor has optimized accuracy for currents from -37.5 to 37.5 A and the analog voltage output is linear for current magnitudes up to 75 A. The ratiometric output voltage is centered at VCC/2 and has a typical error of �2%. It operates from 3 to 5.5 V so it can interface directly to both 3.3 V and 5 V systems.

This current sensor is a carrier board or breakout board forAllegro�s ACS709LLFTR-35BB-T Hall effect-based linear current sensorwith overcurrent fault output; we therefore recommend careful readingof the ACS709datasheet (483k pdf) before using this product. The sensor has anoperating voltage of 3 ? 5.5�V and an output sensitivity of18.5�mV/A when Vcc is 3.3�V (or 28�mV/A when Vcc is5�V). The following list details some of the sensor�s key features:

• Optimized accuracy for bidirectional input current from -37.5 to37.5�A with a linear sensing range from -75 to 75�A (seewarning note below for thermal limitations).
• Conductive path internal resistance is typically 1.1�m? andthe PCB is made with 2-oz copper so very little power is lost in theboard.
• Integrated shield greatly reduces capacitive coupling fromcurrent conductor to die and prevents offset drift in high-sideapplications.
• Use of a Hall effect sensor means the IC is able to electricallyisolate the current path from the sensor�s electronics (up to2.1�kV RMS) which allows the sensor to be inserted anywhere alongthe current path and to be used in applications that require electricalisolation.
• 120�kHz bandwith that can optionally be decreased by addinga capacitor across the board pins marked �FILT�.
• High accuracy and reliability: typical total output error of 2%at room temperature with factory calibration an extremely stablequiescent output voltage
• Automotive-grade operating temperature range of -40�C to 150�C.
• User-settable overcurrent threshold: FAULT pin output latches lowwhen current exceeds the configured threshold for a duration that canbe set through the addition of an external capacitor.

The pads are labeled on the bottom silkscreen as shown in thepicture above. The silkscreen also shows the direction that isinterpreted as positive current flow via the +i arrow.