Hall-Effect Linear Current Sensor Boosts Accuracy
Allegro MicroSystems’ ACS770 linear current sensor IC optimizes device accuracy due to the close proximity of a copper conduction path to a precision, low-offset linear Hall transducer. Applied current flowing through this path generates a magnetic field that the chopper-stabilized biCMOS Hall IC converts into a proportional voltage that’s programmed and calibrated for accuracy at the factory. Proprietary digital temperature-compensation technology improves the IC’s accuracy and temperature stability without influencing the analog output’s high-bandwidth operation. High-level immunity to the current conductor dV/dt and stray electric fields is made possible with the company’s integrated shield technology for low output-voltage ripple and low offset drift in high-side, high-voltage applications. Device output has a positive slope (>VCC/2) when an increasing current flows through the primary copper conduction path (from terminal 4 to terminal 5), which is used for current sampling. Internal resistance of the path is 100 µA typical. Terminals are electrically isolated from the signal leads (pins 1 through 3), allowing for their use in applications requiring electrical isolation without optoisolators or other similar isolation techniques.