ACS709
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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 VRMS 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 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. Package: 24 pin QSOP (suffix LF) 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, Continued on the next page… Approximate Scale Sets resistor divider reference for VOC Noise and bandwidth limiting filter capacitor Fault delay setting capacitor, 22 nF maximum

High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package Description (continued) 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...

High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package Functional Block Diagram VCC Hall Bias FAULT Reset Drain Control Logic Fault Comparator – Sensitivity Trim Signal Recovery Hall Amplifier Terminal List Table Number Pin-out Diagram Sensed current copper conduction path pins. Terminals for current being sensed; fused internally, loop to IP– pins; unidirectional or bidirectional current flow. Sensed current copper conduction path pins. Terminals for current being sensed; fused internally, loop to IP+ pins; unidirectional or bidirectional current flow. No...

High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package COMMON OPERATING CHARACTERISTICS Valid at TA = –40°C to 150°C, VCC = 5 V, unless otherwise specified Characteristic ELECTRICAL CHARACTERISTICS Supply Voltage1 Nominal Supply Voltage Supply Current Output Capacitance Load Output Resistive Load Magnetic Coupling from Device Conductor to Hall Element Internal Filter Resistance2 ¯ L¯ ¯ VIOUT open, ¯ ¯¯¯ ¯ pin high FAU¯ T VIOUT pin to GND VIOUT pin to GND Current flowing from IP+ to IP– pins Switchpoint in VOC safe operating area; assumes INCOMP = 0 A ¯ L¯ ¯ 1 mA...

High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package COMMON OPERATING CHARACTERISTICS (continued) Valid at TA = –40°C to 150°C, VCC = 5 V, unless otherwise specified Characteristic Symbol OVERCURRENT CHARACTERISTICS (continued) Fault Enable (FAULT_EN Pin) Delay9 Overcurrent Fault Response Time Overcurrent Fault Reset Delay Overcurrent Fault Reset Hold Time Overcurrent Input Pin Resistance VOLTAGE REFERENCE CHARACTERISTICS Voltage Reference Output Test Conditions Set FAULT_EN to low, VOC = 0.25 × VCC , COC = 0 F; then run a DC IP exceeding the corresponding...

High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package X20B PERFORMANCE CHARACTERISTICS, TA Range L, valid at TA = – 40°C to 150°C, VCC = 5 V, unless otherwise specified Min. Optimized Accuracy Range Symbol IP(OA) Test Conditions Linear Sensing Range VNOISE(rms) TA = 25°C, Sens = 56 mV/A, Cf = 0, CLOAD = 4.7 nF, RLOAD open IP = 12.5 A, TA = 25°C pk-pk noise (6 sigma noise) is equal to 6 × VNOISE(rms). Lower noise levels than this can be achieved by using Cf for applications requiring narrower bandwidth. See Characteristic Performance page for graphs of noise...

High Bandwidth, Fast Fault Response Current Sensor IC In Thermally Enhanced Package Thermal Characteristics Characteristic Transient Package Thermal Resistance Steady State Package Thermal Resistance Test Conditions Tested with 30 A DC current and based on ACS709 demo board in 1 cu. ft. of still air. Please refer to product FAQs page on Allegro web site for detailed information on ACS709 demo board. Tested with 30 A DC current and based on ACS709 demo board in 1 cu. ft. of still air. Please refer to product FAQs page on Allegro web site for detailed information on ACS709 demo board. ACS709...