Thermally Enhanced, Fully Integrated, Hall-Effect-Based High-Precision Linear Current Sensor IC with 100 µΩ Current Conductor
FEATURES AND BENEFITS
• Industry-leading total output accuracy achieved with new piecewise linear digital temperature compensation of offset and sensitivity
• Industry-leading noise performance through proprietary amplifier and filter design techniques
• 120 kHz typical bandwidth
• 4.1 µs output rise time in response to step input current
• Integrated shield greatly reduces capacitive coupling from current conductor to die due to high dV/dt signals, and prevents offset drift in high-side, high-voltage applications
• Greatly improved total output error through digitally programmed and compensated gain and offset over the full operating temperature range
• Small package size, with easy mounting capability
• Monolithic Hall IC for high reliability
• Ultralow power loss: 100 µΩ internal conductor resistance
• Galvanic isolation allows use in economical, high-side current sensing in high-voltage systems
• 4.5 to 5.5 V, single supply operation
• Output voltage proportional to AC or DC currents
• Factory-trimmed for accuracy
• Extremely stable output offset voltage
DESCRIPTION
The Allegro™ ACS770 family of current sensor ICs provides economical and precise solutions for AC or DC current sensing. Typical applications include motor control, load detection and management, power supply and DC-to-DC converter control, inverter control, and overcurrent fault detection.
The device consists of a precision, low-offset linear Hall circuit with a copper conduction path located near the die. Applied current flowing through this copper conduction path generates a magnetic field that is concentrated by a low magnetic hysteresis core, then converted by the Hall IC into a proportional voltage. Device accuracy is optimized through the close proximity of the magnetic signal to the Hall transducer. A precise, proportional output voltage is provided by the low-offset, chopper-stabilized BiCMOS Hall IC, which is programmed for accuracy at the factory. Proprietary digital temperature compensation technology greatly improves the IC accuracy and temperature stability without influencing the high-bandwidth operation of the analog output.
High-level immunity to current conductor dV/dt and stray electric fields is offered by Allegro proprietary integrated shield technology for low output voltage ripple and low offset drift in high-side, high-voltage applications.
The output of the device has a positive slope (>VCC/2 for bidirectional devices) when an increasing current flows through the primary copper conduction path (from terminal 4 to terminal 5), which is the path used for current sampling. The internal resistance of this conductive path is 100 µΩ typical, providing low power loss.