ACS724 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package FEATURES AND BENEFITS DESCRIPTION Differential Hall sensing rejects common-mode fields The Allegro ACS724 current sensor IC is an economical and 1.2 m primary conductor resistance for low power loss precise solution for AC or DC current sensing in industrial, and high inrush current withstand capability automotive, commercial, and communications systems. The Integrated shield virtually eliminates capacitive small package is ideal for space-constrained applications coupling from current conductor to die, greatly while also saving costs due to reduced board area. Typical suppressing output noise due to high dv/dt transients applications include motor control, load detection and Industry-leading noise performance with greatly management, switched-mode power supplies, and overcurrent improved bandwidth through proprietary amplifier and fault protection. filter design techniques The device consists of a precise, low-offset, linear Hall High-bandwidth 120 kHz analog output for faster sensor circuit with a copper conduction path located near the response times in control applications surface of the die. Applied current flowing through this copper Filter pin allows user to filter the output for improved conduction path generates a magnetic field which is sensed resolution at lower bandwidth by the integrated Hall IC and converted into a proportional Patented integrated digital temperature compensation voltage. The current is sensed differentially in order to reject circuitry allows for near closed loop accuracy over common-mode fields, improving accuracy in magnetically temperature in an open loop sensor noisy environments. The inherent device accuracy is optimized Small-footprint, low-profile SOIC8 package suitable for through the close proximity of the magnetic field to the Hall space-constrained applications transducer. A precise, proportional voltage is provided by the Filter pin simplifies bandwidth limiting for better low-offset, chopper-stabilized BiCMOS Hall IC, which is resolution at lower frequencies programmed for accuracy after packaging. The output of the Continued on the next page device has a positive slope when an increasing current flows through the primary copper conduction path (from pins 1 and Package: 8-Pin SOIC (suffix LC) 2, to pins 3 and 4), which is the path used for current sensing. The internal resistance of this conductive path is 1.2 m typical, TV America Certificate Number: providing low power loss. U8V 14 11 54214 032 CB 14 11 54214 031 CB Certificate Number: The terminals of the conductive path are electrically isolated US-22334-A2-UL from the sensor leads (pins 5 through 8). This allows the ACS724 current sensor IC to be used in high-side current sense applications without the use of high-side differential amplifiers or other costly isolation techniques. Approximate Scale 1:1 Continued on the next page 1 8 VCC IP+ +I P The ACS724 outputs an ACS724 analog signal, V , that IOUT 7 2 changes proportionally VIOUT IP+ with the bidirectional AC I or DC primary sensed P C BYPASS current, I , within the P 6 3 0.1 F specified measurement FILTER IP range. The FILTER pin I P C can be used to decrease LOAD C F the bandwidth in order 4 5 1 nF GND IP to optimize the noise performance. Typical Application ACS724-DS, Rev. 4 Type testedAutomotive-Grade, Galvanically Isolated Current Sensor IC ACS724 With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package Features and Benefits (continued) Description (continued) 5 V, single supply operation The ACS724 is provided in a small, low-profile surface-mount Output voltage proportional to AC or DC current SOIC8 package. The leadframe is plated with 100% matte tin, Factory-trimmed sensitivity and quiescent output voltage for which is compatible with standard lead (Pb) free printed circuit improved accuracy board assembly processes. Internally, the device is Pb-free, except Chopper stabilization results in extremely stable quiescent for flip-chip high-temperature Pb-based solder balls, currently output voltage exempt from RoHS. The device is fully calibrated prior to shipment Nearly zero magnetic hysteresis from the factory. Ratiometric output from supply voltage Selection Guide Sens(Typ) I T PR A Part Number at V = 5 V Packing* CC (A) (C) (mV/A) ACS724LLCTR-05AB-T 5 400 ACS724LLCTR-10AU-T 10 400 ACS724LLCTR-10AB-T 10 200 ACS724LLCTR-20AU-T 20 40 to 150 Tape and Reel, 3000 pieces per reel ACS724LLCTR-20AB-T 20 100 ACS724LLCTR-30AU-T 30 133 ACS724LLCTR-30AB-T 30 66 ACS724LLCTR-50AB-T 50 40 *Contact Allegro for additional packing options. Allegro MicroSystems, LLC 2 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000 www.allegromicro.com