100A ac/dc automotive sensor measures from 200μΩ


Allegro ACS780 ACS781

Allegro has developed a range of high-current automotive-grade current sensors in packages only 1.5mm thick.

The Hall sensors are differential to reject common-mode fields  – from nearby current-carrying conductors, for example.

The devices consist of a precision low-offset linear Hall circuit with a copper conduction path located near the die (see photo).

Applied current generates a magnetic field which the Hall IC converts into a proportional voltage.

Allegro ACS780 ACS781Sensitivity and zero-current output voltage is factory programmed.

Errors are cut by a chopper-stabilized signal path and digital temperature compensation, and proprietary internal shielding increases immunity to dV/dt in the sense wire and and stray electric fields – important for high-side high-voltage applications. Isolation is up to 100V.

Allegro ACS780 ACS781The internal resistance of the oxygen-free copper conductive path is typically 200μΩ, and its thickness provides some over-load protection.

Automotive applications include electric power steering, dc-dc converters, oil pumps and air-con pumps.

Allegro also sees the sensor in industrial applications such as motor drives, plus in computer servers and telecom inverters.

ACS780 are 4.5 to 5.5V parts and ACS781 are 3 to 3.6V.

Part direction range (A) mV/A Package Temp RoHS
ACS781KLRTR-150B-T both ±100
(150 brief)
8.8 7 lead SOT -40 to 125°C Yes
ACS781KLRTR-150U-T uni 0-100
(150 brief)
17.6 7 lead SOT -40 to 125°C Yes
ASEK781KLR-150B-T demo board -40 to 125°C No
ASEK781KLR-150U-T demo board -40 to 125°C No
ACS781LLRTR-050B-T both ±50 26.4 7 lead SOT -40 to 150°C Yes
ACS781LLRTR-050U-T uni 0-50 39.6 7 lead SOT -40 to 150°C Yes
ACS781LLRTR-100B-T both ±100 13.2 7 lead SOT -40 to 150°C Yes
ACS781LLRTR-100U-T uni 0-100 26.4 7 lead SOT -40 to 150°C Yes
ASEK781LLR-050B-T demo board -40 to 150°C No
ASEK781LLR-050U-T demo board -40 to 150°C No
ASEK781LLR-100B-T demo board -40 to 150°C No
ASEK781LLR-100U-T demo board -40 to 150°C No

Table transcription not guaranteed, ACS780 parts are similar


Source link

Leave a Reply