Worcester, Mass. Allegro MicroSystems, Inc. has launched a new bi-directional 1.5 milliohm (mΩ) family of Hall-effect-based linear current sensors. The new ACS706 devices provide a 20-A dynamic range and increased isolation voltage up to 1600 Vrms.
Designed for current sensing in industrial, commercial and communications systems, the ACS706 devices are bi-directional sensors that can measure either AC or DC currents. The power leadframe is designed for extremely low power loss, and is electrically isolated from the sensor signal leads. This isolation allows ACS706 sensors to be used in applications requiring electrical isolation without the addition of other isolation components, according to the company. Typical applications include motor control, load detection and management, switched-mode power supplies, and overcurrent fault protection.
The ACS706 devices include a precision, low-offset linear Hall sensor circuit with a copper conduction path located near the surface of the die. Applied current flowing through this copper conduction path generates a magnetic field which is sensed by the integrated Hall IC and converted into a proportional voltage. Device accuracy is optimized through the close proximity of the magnetic signal to the Hall transducer. A precise, proportional voltage is provided by the low-offset, chopper-stabilized BiCMOS Hall IC, which is programmed for accuracy at the factory.
The output of the devices have a positive slope when an increasing current flows through the primary copper conduction path (from pins 1 and 2 to pins 3 and 4), which is the path used for current sensing. The internal resistance of this conductive path is typically 1.5 mΩ, providing low power loss. The thickness of the copper conductor allows survival of the device at up to 3 times the overcurrent conditions, according to the company. The terminals of the conductive path are electrically isolated from the sensor leads (pins 5 through 8).
Available in a small surface-mount SOIC-8 package, the leadframe is plated with 100% matte tin, which is compatible with standard lead-free printed-circuit-board assembly processes. Internally, the flip-chip uses high-temperature lead-based solder balls, which is currently exempt from the RoHS directive. These devices are fully calibrated prior to shipment from the factory. Click here for more product information.
The ACS706 family is priced at $1.40 in quantities of 10,000. Delivery is eight weeks.
Allegro MicroSystems, Inc., 1-508-853-5000, www.allegromicro.com