High-Performance Power and Hall-Effect Sensor ICs

ACS709
High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package

Features and Benefits

Industry-leading noise performance with 120 kHz bandwidth through proprietary amplifier and filter design techniques
Integrated shield greatly reduces capacitive coupling from current conductor to die due to high dV/dt, and prevents offset drift in high-side applications
Small footprint surface mount QSOP24 package
2100 V_RMS isolation voltage between primary current path and sensor IC electronics
1.1 mΩ primary conductor resistance for low power loss
User-settable Overcurrent Fault level
Overcurrent Fault signal typically responds to an overcurrent condition in <2 µs
Filter pin capacitor sets analog signal bandwidth
±2% typical output error
3 to 5.5 V, single supply operation
Factory trimmed sensitivity, quiescent output voltage, and associated temperature coefficients
Chopper stabilization results in extremely stable quiescent output voltage
Ratiometric output from supply voltage

Applications

Motor control and protection
Load management and overcurrent detection
Power conversion and battery monitoring / UPS systems

Description

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.

Typical Applications

Functional Block Diagram

Complete Part Numbers
Part Number	Package Type	RoHS Compliant	Part Composition/ RoHS Data	Temperature	Comments	Samples	Distributor Stock
ACS709LLFTR-20BB-T	24-lead QSOP	Yes	view data	-40 °C to 150 °C	new	Contact Local Sales Representative or check distributor stock
ACS709LLFTR-35BB-T	24-lead QSOP	Yes	view data	-40 °C to 150 °C	new	Contact Local Sales Representative or check distributor stock

Allegro's products are not to be used in life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the failure of that life support device or system, or to affect the safety or effectiveness of that device or system.

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ACS709 High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package