The Allegro ACS709 current sensor IC provides economical and precise means for current sensing applications in industrial, automotive, commercial, and communications systems. The device is offered in a small footprint surface mount package that allows easy implementation in customer applications.
The ACS709 consists of a precision linear Hall sensor integrated circuit with a copper conduction path located near the surface of the silicon die. Applied current flows through the copper conduction path, and the analog output voltage from the Hall sensor IC linearly tracks the magnetic field generated by the applied current. The accuracy of the ACS709 is maximized with this patented packaging configuration because the Hall element is situated in extremely close proximity to the current to be measured.
High level immunity to current conductor dV/dt and stray electric fields, offered by Allegro proprietary integrated shield technology, guarantees low output ripple and low offset drift in high-side applications.
The voltage on the Overcurrent Input (VOC pin) allows customers to define an overcurrent fault threshold for the device. When the current flowing through the copper conduction path (between the IP+ and IP– pins) exceeds this threshold, the open drain Overcurrent Fault pin will transition to a logic low state. Factory programming of the linear Hall sensor IC inside of the ACS709 results in exceptional accuracy in both analog and digital output signals.
The internal resistance of the copper path used for current sensing is typically 1.1 mΩ, for low power loss. Also, the current conduction path is electrically isolated from the low voltage device inputs and outputs. This allows the ACS709 family of sensor ICs to be used in applications requiring electrical isolation, without the use of opto-isolators or other costly isolation techniques.