The Allegro ACS714 provides economical and precise solutions for AC or DC current sensing in automotive systems. The device package allows for easy implementation by the customer. Typical applications include motor control, load detection and management, switch-mode power supplies, and overcurrent fault protection.
The device consists of a precise, low-offset, linear Hall 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 the Hall IC converts 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 after packaging.
The output of the device has a positive slope (>VIOUT(Q)) 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 sampling. The internal resistance of this conductive path is 1.2 m typical, providing low power loss. The thickness of the copper conductor allows survival of the device at up to 5× overcurrent conditions. The terminals of the conductive path are electrically isolated from the signal leads (pins 5 through 8). This allows the ACS714 to be used in applications requiring electrical isolation without the use of opto-isolators or other costly isolation techniques.
The ACS714 is provided in a small, surface mount SOIC8 package.
The leadframe is plated with 100% matte tin, which is compatible with standard lead (Pb) free printed circuit board assembly processes. Internally, the device is Pb-free, except for flip-chip high-temperature Pb-based solder balls, currently exempt from RoHS. The device is fully calibrated prior to shipment from the factory.
Features and Benefits
Low-noise analog signal path
Device bandwidth is set via the FILTER pin
5 μs output rise time in response to step input current
80 kHz bandwidth
Total output error 1.5% typical, at TA= 25°C
Small footprint, low-profile SOIC8 package
1.2 m internal conductor resistance
2.1 kVRMS minimum isolation voltage from pins 1-4 to pins 5-8
5.0 V, single supply operation
66 to 185 mV/A output sensitivity
Output voltage proportional to AC or DC currents
Factory-trimmed for accuracy
Extremely stable output offset voltage
Nearly zero magnetic hysteresis
Ratiometric output from supply voltage
Operating temperature range, –40°C to 150°C