Typical Application - SparkFun Electronics

1 IP+IP+IP IP IP5 GND2413 ACS71278+5 FCF1 nFApplication 1. The ACS712 outputs an analog signal, VOUT . that varies linearly with the uni- or bi-directional AC or DC primary sensed current , IP , within the range specified. CF is recommended for noise management, with values that depend on the Allegro ACS712 provides economical and precise solutions for AC or DC current sensing in industrial, commercial, and communications systems. The device package allows for easy implementation by the customer.

2 Typical applications include motor control, load detection and management, switched-mode power supplies, and overcurrent fault device consists of a precise, low-offset, linear Hall sensor 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 is sensed by the integrated Hall IC and converted into a proportional voltage . Device accuracy is optimized through the close proximity of the magnetic signal to the Hall transducer.

3 A precise, proportional voltage is provided by the low-offset, chopper-stabilized BiCMOS Hall IC, which is programmed for accuracy after 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 sensing. The internal resistance of this conductive path is m Typical , providing low power ACS712-DS, Rev. 7 Features and Benefits Low-noise analog signal path Device bandwidth is set via the new FILTER pin 5 s output rise time in response to step input current 80 kHz bandwidth Total output error at TA = 25 C Small footprint, low-profile SOIC8 package m internal conductor resistance kVRMS minimum isolation voltage from pins 1-4 to pins 5-8 V.

4 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 voltageFully Integrated, Hall Effect-Based Linear current Sensor with kVRMS voltage Isolation and a Low-Resistance current ConductorContinued on the next Scale 1:1 Package: 8 Lead SOIC (suffix LC) Typical ApplicationT V AmericaCertificate Number:U8V 06 05 54214 010 Fully Integrated, Hall Effect-Based Linear current Sensor with kVRMS voltage Isolation and a Low-Resistance current ConductorACS7122 Allegro MicroSystems, Northeast CutoffWorcester, Massachusetts 01615-0036 ; Maximum RatingsCharacteristicSymbolNotesRatingUn itsSupply voltage VCC8 VReverse Supply VoltageVRCC VoltageVIOUT8 VReverse output VoltageVRIOUT Isolation VoltageVISOPins 1-4 and 5-8.

5 60 Hz, 1 minute, TA=25 C2100 VVoltage applied to leadframe (Ip+ pins), based on IEC 60950184 VpeakBasic Isolation VoltageVISO(bsc)Pins 1-4 and 5-8; 60 Hz, 1 minute, TA=25 C1500 VVoltage applied to leadframe (Ip+ pins), based on IEC 60950354 VpeakOutput current Source IIOUT(Source) 3mAOutput current Sink IIOUT(Sink)10mAOvercurrent Transient ToleranceIP1 pulse, 100 ms100 ANominal Operating Ambient TemperatureTARange E 40 to 85 CMaximum Junction TemperatureTJ(max)165 CStorage TemperatureTstg 65 to 170 CSelection GuidePart NumberPacking*TA ( C)Optimized Range, IP(A)Sensitivity, Sens (Typ) (mV/A)

6 ACS712 ELCTR-05B-TTape and reel, 3000 pieces/reel 40 to 85 5185 ACS712 ELCTR-20A-TTape and reel, 3000 pieces/reel 40 to 85 20100 ACS712 ELCTR-30A-TTape and reel, 3000 pieces/reel 40 to 85 3066*Contact Allegro for additional packing 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 sensor leads (pins 5 through 8). This allows the ACS712 current sensor to be used in applications requiring electrical isolation without the use of opto-isolators or other costly isolation ACS712 is provided in a small, surface mount SOIC8 package.

7 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 (continued)ParameterSpecificationFire and Electric No. 60950-1-03UL 60950-1:2003EN 60950-1:2001 Fully Integrated, Hall Effect-Based Linear current Sensor with kVRMS voltage Isolation and a Low-Resistance current ConductorACS7123 Allegro MicroSystems, Northeast CutoffWorcester, Massachusetts 01615-0036.

8 (Pin 8)(Pin 7)VIOUTRF(INT)GND(Pin 5)FILTER(Pin 6)Dynamic Offset CancellationIP+(Pin 1)IP+(Pin 2)IP (Pin 3)IP (Pin 4)SenseTrimSignalRecoverySense TemperatureCoefficient Trim0 AmpereOffset AdjustHall CurrentDrive+5 VIP+IP+IP IP VCCVIOUTFILTERGND12348765 Terminal List TableNumberNameDescription1 and 2IP+Terminals for current being sensed; fused internally3 and 4IP Terminals for current being sensed; fused internally5 GNDS ignal ground terminal6 FILTERT erminal for external capacitor that sets bandwidth7 VIOUTA nalog output signal8 VCCD evice power supply terminalFunctional Block DiagramPin-out DiagramFully Integrated, Hall Effect-Based Linear current Sensor with kVRMS voltage Isolation and a Low-Resistance current ConductorACS7124 Allegro MicroSystems, Northeast CutoffWorcester, Massachusetts 01615-0036.

9 OPERATING CHARACTERISTICS1 over full range of TA , CF = 1 nF, and VCC = 5 V, unless otherwise specifiedCharacteristicSymbolTest CHARACTERISTICSS upply CurrentICCVCC = V, output open 1013mAOutput Capacitance LoadCLOADVIOUT to GND 10nFOutput Resistive LoadRLOADVIOUT to k Primary Conductor ResistanceRPRIMARYTA = 25 C m Rise TimetrIP = IP(max), TA = 25 C, COUT = open 5 sFrequency Bandwidthf 3 dB, TA = 25 C; IP is 10 A peak-to-peak 80 kHzNonlinearityELINOver full range of IP %SymmetryESYMOver full range of IP98100102%Zero current output VoltageVIOUT(Q)Bidirectional.

10 IP = 0 A, TA = 25 C VCC VPower-On TimetPOOutput reaches 90% of steady-state level, TJ = 25 C, 20 A present on leadframe 35 sMagnetic Coupling2 12 G/AInternal Filter Resistance3RF(INT) 1 Device may be operated at higher primary current levels, IP, and ambient, TA , and internal leadframe temperatures, TA , provided that the Maximum Junction Temperature, TJ(max), is not = mT. 3RF(INT) forms an RC circuit via the FILTER THERMAL Internal Leadframe TemperatureTAE range 40 85 CValueUnitsJunction-to-Lead Thermal Resistance2R JLMounted on the Allegro ASEK 712 evaluation board5 C/WJunction-to-Ambient Thermal ResistanceR JAMounted on the Allegro 85-0322 evaluation board, includes the power con-sumed by the board23 C/W1 Additional thermal information is available on the Allegro Allegro evaluation board has 1500 mm2 of 2 oz.