ACS711 Hall Effect Linear Current Sensor with Overcurrent Fault Output for <100 V Isolation Applications Features and Benefits Description The Allegro(R) ACS711 provides economical and precise solutions for AC or DC current sensing in <100 V audio, communications systems, and white goods applications. The device package allows for easy implementation by the customer. Typical applications include circuit protection, current monitoring, and motor and inverter control. No external sense resistor required; single package solution 1.2 m internal conductor resistance; reduced power loss Economical low- and high-side current sensing Output voltage proportional to AC or DC currents 12.5 A and 25 A full scale sensing ranges T trips and latches at 100% of full-scale current Overcurrent FAUL Low-noise analog signal path 100 kHz bandwidth Small footprint, low-profile SOIC8 package 3.0 to 5.5 V, single supply operation Integrated electrostatic shield for output stability Factory-trimmed for accuracy Extremely stable output offset voltage Zero magnetic hysteresis Ratiometric output from supply voltage The device consists of a 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. The output of the device has a positive slope proportional to the current flow from IP+ to IP- (pins 1 and 2, to pins 3 and 4). The internal resistance of this conductive path is 1.2 m typical, providing a non-intrusive measurement interface that saves power in applications that require energy efficiency. Package: 8 Lead SOIC (suffix LC) The ACS711 is optimized for low-side current sensing applications, although the terminals of the conductive path are electrically isolated from the sensor leads (pins 5 through 8), providing sufficient internal creepage and clearance dimensions for a low AC or DC working voltage applications. The thickness Approximate Scale 1:1 Continued on the next page... Typical Application 1 2 IP+ VCC IP+ VIOUT 8 3 4 IP- IP- FAULT GND CBYP 0.1 F 7 ACS711 IP +3.3 V RPU CLOAD 6 5 Application 1. The ACS711 outputs an analog signal, VIOUT , that varies linearly with the bi-directional AC or DC primary AULT pin trips current, IP , within the range specified. The F when IP reaches 100% of its full-scale current. ACS711-DS, Rev. 3 Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications ACS711 Description (continued) of the copper conductor allows survival of the device at up to 5x overcurrent conditions. 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 factory. The ACS711 is provided in a small, surface mount SOIC8 package. The leadframe is plated with 100% matte tin, which is compatible with standard lead (Pb) free printed circuit board assembly processes. Selection Guide Packing1 Part Number TA (C) Optimized Accuracy Range, IP (A) Sensitivity, Sens (Typ) (mV/A) 110 ACS711ELCTR-12AB-T2 Tape and reel, 3000 pieces/reel -40 to 85 12.5 ACS711ELCTR-25AB-T2 Tape and reel, 3000 pieces/reel -40 to 85 25 55 ACS711KLCTR-12AB-T2 Tape and reel, 3000 pieces/reel -40 to 125 12.5 110 ACS711KLCTR-25AB-T2 Tape and reel, 3000 pieces/reel -40 to 125 25 55 1Contact Allegro for additional packing options. 2Sensitivity measured with V CC = 3.3 V. Absolute Maximum Ratings Characteristic Symbol Supply Voltage Rating Units VCC Notes 7 V Reverse Supply Voltage VRCC -0.1 V Output Voltage VIOUT 7 V Reverse Output Voltage VRIOUT -0.1 V 100 VAC peak or VDC 7 V Working Voltage for Basic Isolation AULT Pin Voltage F VWORKING VFAULT Overcurrent Transient Tolerance IPOC Nominal Operating Ambient Temperature Maximum Junction Temperature Voltage applied between pins 1-4 and 5-8 TA 1 pulse, 100 ms 100 A Range E -40 to 85 C Range K -40 to 125 C TJ(max) 165 C Tstg -65 to 170 C Value Units Storage Temperature Thermal Characteristics Characteristic Symbol Test Conditions1 Package Thermal Resistance, Junction to Lead RJL Mounted on Allegro ASEK 711 evaluation board 5 C/W Package Thermal Resistance, Junction to Ambient2 RJA Mounted on Allegro 85-0404 evaluation board, includes the power consumed by the board 23 C/W 1Additional thermal information available on the Allegro website evaluation board has 1500 mm2 of 2 oz. copper on each side, connected to pins 1 and 2, and to pins 3 and 4, with thermal vias connecting the layers. Performance values include the power consumed by the PCB. Further details on the board are available from the Frequently Asked Questions document on our website. 2The Allegro Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 2 Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications ACS711 Functional Block Diagram VCC VCC RPU Master Current Supply Current Fault Comparator To all subcircuits CBYP FAULT D 240 k Power-on Reset Hall Current Drive IP+ Sensitivity Temperature Coefficient Trim Dynamic Offset Cancellation IP+ Reset IP VIOUT Signal Recovery CLOAD Sensitivity Trim 0 Ampere Offset Adjust IP GND Pin-out Diagram IP+ 1 8 VCC IP+ 2 7 VIOUT IP- 3 6 FAULT IP- 4 5 GND Terminal List Table Number Name 1 and 2 IP+ Terminals for current being sensed; fused internally 3 and 4 IP- Terminals for current being sensed; fused internally 5 GND 6 AULT F 7 VIOUT 8 VCC Description Signal ground terminal Overcurrent fault; active low Analog output signal Device power supply terminal Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 3 Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications ACS711 COMMON OPERATING CHARACTERISTICS over full range of TA and VCC = 3.3 V, unless otherwise specified Characteristic Symbol Test Conditions Min. Typ. Max. Units 3 3.3 5.5 V ELECTRICAL CHARACTERISTICS Supply Voltage1 Supply Current VCC VCC = 3.3 V, output open - 4 5.5 mA Output Capacitance Load CLOAD ICC VIOUT to GND - - 1 nF Output Resistive Load RLOAD VIOUT to GND 15 - - k TA = 25C - 1.2 - m IP = IPMAX, TA = 25C, COUT = open - 3.5 - s tPROP IP = IP(max), TA = 25C, COUT = open - 1.2 - s tRESPONSE IP = IP(max), TA = 25C, COUT = open - 4.6 - s BWI -3 dB, TA = 25C - 100 - kHz Nonlinearity ELIN Over full range of IP - 1 - % Symmetry ESYM Apply full scale IP - 100 - % VCC- 0.3 - - V Primary Conductor Resistance RIP VIOUT Rise Time tr Propagation Delay Time Response Time Internal Bandwidth2 VIOUT Saturation Voltages VIOH VIOL Quiescent Output Voltage Power-On Time - - 0.3 V IP = 0 A, TA = 25C - VCC / 2 - V Output reaches 90% of steady-state level, TA = 25C, 20 A present on primary conductor - 35 - s IFAULT - 1 x IP - A RPU 1 - - k VOH - VCC- 0.3 - V RPU = 1 k - 0.3 - V Measured from | IP | > | IFAULT | to VFAULT VOL - 1.3 - s VIOUT(Q) tPO AUL T Pin Characteristics F AULT Operating Point F AULT Output Pullup F Resistor AULT Output Voltage F VOL AULT Response Time F tFAULT VCC Off Voltage Level for Fault Reset3 VCCFR - - 200 mV VCC Off Duration for Fault Reset3 tCCFR 100 - - s 1Devices are programmed for maximum accuracy at 3.3 V V CC levels. The device contains ratiometry circuits that accurately alter the 0 A Output Voltage and Sensitivity level of the device in proportion to the applied VCC level. However, as a result of minor nonlinearities in the ratiometry circuit additional output error will result when VCC varies from the 3.3 V VCC level. Customers that plan to operate the device from a 5 V regulated supply should contact their local Allegro sales representative regarding expected device accuracy levels under these bias conditions. 2Calculated using the formula BW = 0.35 / t . I r 3After the F AULT pin is latched low, the only way to reset it is through a power-off and power-on cycle on the VCC pin. To get a guaranteed fault reset, VCC must stay below VCCFR for a period greater than tCCFR before settling to the normal operation voltage (3 to 5.5 V). Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 4 Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications ACS711 x12.5A PERFORMANCE CHARACTERISTICS for E TEMPERATURE RANGE TA = 25C and VCC = 3.3 V, unless otherwise specified Characteristic Optimized Accuracy Range Sensitivity Noise2 Electrical Offset Voltage Total Output Error3 Symbol Test Conditions Min. Typ. Max. -12.5 - 12.5 A Over full range of IP - 110 - mV/A Full scale of IP applied for 5 ms, TA = -40C to 25C - 110 - mV/A Full scale of IP applied for 5 ms, TA = 25C to 85C - 110 - mV/A VNOISE TA = 25C, no external low pass filter on VIOUT - 11 - mV VOE(TA) IP = 0 A, TA = 25C - 5 - mV VOE(TOP)HT IP = 0 A, TA = 25C to 85C - 40 - mV VOE(TOP)LT IP = 0 A, TA = -40C to 25C - 50 - mV - 5 - % IP Sens ETOT IP = 12.5 A,TA = -40C to 85C Units 1See Characteristic Performance Data for parameter distributions over temperature. 23 sigma noise voltage. 3Percentage of I , with I = 12.5 A. P P x12.5A PERFORMANCE CHARACTERISTICS for K TEMPERATURE RANGE1 TA = 25C and VCC = 3.3 V, unless otherwise specified Characteristic Optimized Accuracy Range Sensitivity Noise2 Electrical Offset Voltage Symbol Test Conditions Min. Typ. Max. -12.5 - 12.5 A Over full range of IP - 110 - mV/A Full scale of IP applied for 5 ms, TA = -40C to 25C - 110 - mV/A Full scale of IP applied for 5 ms, TA = 25C to 125C - 110 - mV/A VNOISE TA = 25C, no external low pass filter on VIOUT - 11 - mV VOE(TA) IP = 0 A, TA = 25C IP Sens VOE(TOP)HT IP = 0 A, TA = 25C to 125C VOE(TOP)LT IP = 0 A, TA = -40C to 25C Total Output Error3 ETOT IP = 12.5 A,TA = -40C to 125C Units - 5 - mV - 40 - mV - 50 - mV - 5 - % 1See Characteristic Performance Data for parameter distributions over temperature. 23 sigma noise voltage. 3Percentage of I , with I = 12.5 A. P P Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 5 Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications ACS711 x25A PERFORMANCE CHARACTERISTICS for E TEMPERATURE RANGE TA = 25C and VCC = 3.3 V, unless otherwise specified Characteristic Optimized Accuracy Range Sensitivity Noise2 Electrical Offset Voltage Total Output Error3 Symbol Test Conditions Min. Typ. Max. -25 - 25 A Over full range of IP - 55 - mV/A Full scale of IP applied for 5 ms, TA = -40C to 25C - 55 - mV/A Full scale of IP applied for 5 ms, TA = 25C to 85C - 55 - mV/A VNOISE TA = 25C, no external low pass filter on VIOUT - 8 - mV VOE(TA) IP = 0 A, TA = 25C - 5 - mV VOE(TOP)HT IP = 0 A, TA = 25C to 85C - 30 - mV VOE(TOP)LT IP = 0 A, TA = -40C to 25C - 35 - mV - 4 - % IP Sens ETOT IP =25 A, TA = -40C to 85C Units 1See Characteristic Performance Data for parameter distributions over temperature. 23 sigma noise voltage. 3Percentage of I , with I = 25 A. P P x25A PERFORMANCE CHARACTERISTICS for K TEMPERATURE RANGE1 TA = 25C and VCC = 3.3 V, unless otherwise specified Characteristic Optimized Accuracy Range Sensitivity Noise2 Electrical Offset Voltage Symbol Test Conditions Min. Typ. Max. -25 - 25 A Over full range of IP - 55 - mV/A Full scale of IP applied for 5 ms, TA = -40C to 25C - 55 - mV/A Full scale of IP applied for 5 ms, TA = 25C to 125C - 55 - mV/A VNOISE TA = 25C, no external low pass filter on VIOUT - 8 - mV VOE(TA) IP = 0 A, TA = 25C IP Sens VOE(TOP)HT IP = 0 A, TA = 25C to 125C VOE(TOP)LT IP = 0 A, TA = -40C to 25C Total Output Error3 ETOT IP =25 A, TA = -40C to 125C Units - 5 - mV - 30 - mV - 35 - mV - 4 - % 1See Characteristic Performance Data for parameter distributions over temperature. 23 sigma noise voltage. 3Percentage of I , with I = 25 A. P P Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 6 Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications ACS711 Characteristic Performance Data Data taken using the ACS711KLC-12A, VCC = 3.3 V Accuracy Data Electrical Offset Voltage versus Ambient Temperature 114 60 113 Sens (mV/A) 80 40 VOE (mV) Sensitivity versus Ambient Temperature 20 0 112 111 110 -20 109 -40 108 -60 -60 -40 -20 0 20 40 60 80 100 120 107 -60 140 -40 -20 0 20 TA (C) Nonlinearity versus Ambient Temperature 101.5 1.5 101.0 ESYM (%) ELIN (%) 1.0 0.5 0 100 120 140 100.5 100.0 99.0 -1.0 -1.5 -40 -20 0 20 40 60 80 100 120 98.5 -60 140 -40 -20 0 20 TA (C) 40 60 80 100 120 140 TA (C) Total Output Error versus Ambient Temperature Fault Operating Point versus Ambient Temperature 8 16 6 14 4 12 2 IFAULT(A) ETOT (%) 80 99.5 -0.5 0 -2 10 8 6 4 -4 -6 -60 60 Symmetry versus Ambient Temperature 2.0 -60 40 TA (C) 2 -40 -20 0 20 40 60 80 100 120 0 140 -60 TA (C) -40 -20 0 20 40 60 80 100 120 140 TA (C) Typical Maximum Limit Mean Typical Minimum Limit Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 7 Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications ACS711 Characteristic Performance Data Data taken using the ACS711KLC-25A, VCC = 3.3 V Accuracy Data Electrical Offset Voltage versus Ambient Temperature 40 57.0 30 56.5 Sens (mV/A) 20 VOE (mV) Sensitivity versus Ambient Temperature 10 0 -10 55.5 55.0 54.5 -20 54.0 -30 -40 -60 56.0 -40 -20 0 20 40 60 80 100 120 53.5 -60 140 -40 -20 0 20 TA (C) Nonlinearity versus Ambient Temperature 120 140 100.4 0.5 ESYM (%) ELIN (%) 100 100.6 0 100.2 100.0 99.8 99.6 -0.5 99.4 -1.0 99.2 99.0 -40 -20 0 20 40 60 80 100 120 140 -60 -40 -20 0 20 TA (C) 40 60 80 100 120 140 TA (C) Total Output Error versus Ambient Temperature Fault Operating Point versus Ambient Temperature 5 30 4 25 3 2 20 1 IFAULT (A) ETOT (%) 80 100.8 1.0 0 -1 -2 15 10 5 -3 -4 -60 60 Symmetry versus Ambient Temperature 1.5 -1.5 -60 40 TA (C) -40 -20 0 20 40 60 80 100 120 0 140 -60 TA (C) -40 -20 0 20 40 60 80 100 120 140 TA (C) Typical Maximum Limit Mean Typical Minimum Limit Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 8 Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications ACS711 Characteristic Performance Data Data taken using the ACS711KLC-25A Timing Data Rise Time Propagation Delay Time VIOUT (0.5 V/div.) VIOUT (0.5 V/div.) IP (10 A/div.) IP (10 A/div.) 3.47 s 1.24 s t (2 s/div.) t (2 s/div.) Response Time Fault Response VIOUT (0.5 V/div.) IP (10 A/div.) IP (10 A/div.) 1.28 s 4.62 s Fault (2 V/div.) t (2 s/div.) t (2 s/div.) Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 9 ACS711 Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications Definitions of Accuracy Characteristics Sensitivity (Sens). The change in sensor output in response to a 1 A change through the primary conductor. The sensitivity is the product of the magnetic circuit sensitivity (G / A) and the linear IC amplifier gain (mV/G). The linear IC amplifier gain is programmed at the factory to optimize the sensitivity (mV/A) for the full-scale current of the device. Noise (VNOISE). The product of the linear IC amplifier gain (mV) and the noise floor for the Allegro Hall effect linear IC. The noise floor is derived from the thermal and shot noise observed in Hall elements. Dividing the noise (mV) by the sensitivity (mV/A) provides the smallest current that the device is able to resolve. Linearity (ELIN). The degree to which the voltage output from the sensor varies in direct proportion to the primary current through its full-scale amplitude. Nonlinearity in the output can be attributed to the saturation of the flux concentrator approaching the full-scale current. The following equation is used to derive the linearity: where VIOUT_full-scale amperes = the output voltage (V) when the { [ 100 1- gain x % sat ( VIOUT_full-scale amperes - VIOUT(Q) ) 2 (VIOUT_half-scale amperes - VIOUT(Q) ) Accuracy (ETOT). The accuracy represents the maximum deviation of the actual output from its ideal value. This is also known as the total ouput error. The accuracy is illustrated graphically in the output voltage versus current chart below. Ratiometry. The ratiometric feature means that its 0 A output, VIOUT(Q), (nominally equal to VCC/2) and sensitivity, Sens, are proportional to its supply voltage, VCC . The following formula is used to derive the ratiometric change in 0 A output voltage, VIOUT(Q)RAT (%). 100 VIOUT(Q)VCC / VIOUT(Q)3.3V The ratiometric change in sensitivity, SensRAT (%), is defined as: 100 [{ SensVCC / Sens3.3V VCC / 3.3 V Accuracy at 0 A and at Full-Scale Current Increasing VIOUT(V) Accuracy Over $Temp erature Symmetry (ESYM). The degree to which the absolute voltage output from the sensor varies in proportion to either a positive or negative full-scale primary current. The following formula is used to derive symmetry: Accuracy 25C Only Average VIOUT Accuracy Over $Temp erature VIOUT_+ full-scale amperes - VIOUT(Q) VIOUT(Q) - VIOUT_-full-scale amperes Quiescent output voltage (VIOUT(Q)). The output of the sensor when the primary current is zero. For a unipolar supply voltage, it nominally remains at VCC 2. Thus, VCC = 3.3 V translates into VIOUT(Q) = 1.65 V. Variation in VIOUT(Q) can be attributed to the resolution of the Allegro linear IC quiescent voltage trim and thermal drift. Electrical offset voltage (VOE). The deviation of the device output from its ideal quiescent value of VCC / 2 due to nonmagnetic causes. To convert this voltage to amperes, divide by the device sensitivity, Sens. Output Voltage versus Sensed Current sensed current approximates full-scale IP . 100 VCC / 3.3 V Accuracy 25C Only IP(min) -IP (A) +IP (A) Full Scale IP(max) 0A Accuracy 25C Only Accuracy Over $Temp erature Decreasing VIOUT(V) Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 10 ACS711 Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications Definitions of Dynamic Response Characteristics Power-On Time (tPO). When the supply is ramped to its operating voltage, the device requires a finite time to power its internal components before responding to an input magnetic field. Power-On Time, tPO , is defined as the time it takes for the output voltage to settle within 10% of its steady state value under an applied magnetic field, after the power supply has reached its minimum specified operating voltage, VCC(min), as shown in the chart at right. Rise time (tr). The time interval between a) when the sensor reaches 10% of its full scale value, and b) when it reaches 90% of its full scale value. The rise time to a step response is used to derive the bandwidth of the current sensor, in which (-3 dB) = 0.35 / tr. Both tr and tRESPONSE are detrimentally affected by eddy current losses observed in the conductive IC ground plane. I (%) Primary Current 90 Transducer Output 10 0 Rise Time, tr t Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 11 Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications ACS711 Package LC, 8-pin SOIC 4.90 0.10 8 0 8 0.65 6.00 0.20 2 Branded Face 8X SEATING PLANE 0.10 C 1.27 BSC 1 1.27 0.40 0.25 BSC 0.51 0.31 5.60 1.04 REF A 1 C 1.27 1.75 0.25 0.17 3.90 0.10 8 C 2 PCB Layout Reference View SEATING PLANE GAUGE PLANE NNNNNNN TPP-AAA LLLLL 1.75 MAX 0.25 0.10 1 B Standard Branding Reference View For Reference Only; not for tooling use (reference MS-012AA) Dimensions in millimeters Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown A Terminal #1 mark area N = Device part number T = Device temperature range P = Package Designator A = Amperage L = Lot number Belly Brand = Country of Origin B Branding scale and appearance at supplier discretion C D Reference land pattern layout (reference IPC7351 SOIC127P600X175-8M); all pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary to meet application process requirements and PCB layout tolerances Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 12 Hall Effect Linear Current Sensor with Overcurrent Fault Output for < 100 V Isolation Applications ACS711 Revision History Revision Revision Date Rev. 3 January 5, 2012 Description of Revision Update description Copyright (c)2008-2012, Allegro MicroSystems, Inc. Allegro MicroSystems, Inc. reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the performance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the information being relied upon is current. 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. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringement of patents or other rights of third parties which may result from its use. For the latest version of this document, visit our website: www.allegromicro.com Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 13