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 • 1.2 mΩ primary conductor resistance for low power loss and high inrush current withstand capability • Integrated shield virtually eliminates capacitive coupling from current conductor to die, greatly suppressing output noise due to high dv/dt transients • Industry-leading noise performance with greatly improved bandwidth through proprietary amplifier and filter design techniques • High-bandwidth 120 kHz analog output for faster response times in control applications • Filter pin allows user to filter the output for improved resolution at lower bandwidth • Patented integrated digital temperature compensation circuitry allows for near closed loop accuracy over temperature in an open loop sensor • Small-footprint, low-profile SOIC8 package suitable for space-constrained applications • Filter pin simplifies bandwidth limiting for better resolution at lower frequencies The Allegro™ ACS724 current sensor IC is an economical and precise solution for AC or DC current sensing in industrial, automotive, commercial, and communications systems. The small package is ideal for space-constrained applications while also saving costs due to reduced board area. Typical applications include motor control, load detection and management, switched-mode power supplies, and overcurrent fault protection. The 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. The current is sensed differentially in order to reject common-mode fields, improving accuracy in magnetically noisy environments. The inherent device accuracy is optimized through the close proximity of the magnetic field to the Hall transducer. A precise, proportional voltage is provided by the low-offset, chopper-stabilized BiCMOS Hall IC, which is programmed for accuracy after packaging. The output of the device has a positive slope 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 1.2 mΩ typical, providing low power loss. Continued on the next page… Package: 8-Pin SOIC (suffix LC) pe d Ty ste te TÜV America Certificate Number: U8V 14 11 54214 032 CB 14 11 54214 031 CB Certificate Number: US-22334-A2-UL The terminals of the conductive path are electrically isolated 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 1 +IP 2 IP+ IP+ VCC –IP 4 IP– IP– 8 ACS724 VIOUT IP 3 Continued on the next page… FILTER GND 7 CBYPASS 0.1 µF 6 5 CF 1 nF Typical Application ACS724-DS, Rev. 3 CLOAD The ACS724 outputs an analog signal, VIOUT , that changes proportionally with the bidirectional AC or DC primary sensed current, IP , within the specified measurement range. The FILTER pin can be used to decrease the bandwidth in order to optimize the noise performance. Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 Features and Benefits (continued) Description (continued) • 5 V, single supply operation • Output voltage proportional to AC or DC current • Factory-trimmed sensitivity and quiescent output voltage for improved accuracy • Chopper stabilization results in extremely stable quiescent output voltage • Nearly zero magnetic hysteresis • Ratiometric output from supply voltage The ACS724 is provided in a small, low-profile 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. 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. Selection Guide Part Number IPR (A) Sens(Typ) at VCC = 5 V (mV/A) ACS724LLCTR-10AU-T 10 400 ACS724LLCTR-10AB-T ±10 ACS724LLCTR-20AU-T 20 TA (°C) Packing* -40 to 150 Tape and Reel, 3000 pieces per reel 200 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 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 2 ACS724 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package SPECIFICATIONS Absolute Maximum Ratings Characteristic Supply Voltage Symbol Notes VCC Rating Units 6 V Reverse Supply Voltage VRCC –0.1 V Output Voltage VIOUT VCC + 0.5 V Reverse Output Voltage VRIOUT Operating Ambient Temperature TA Range L –0.1 V –40 to 150 °C Junction Temperature TJ(max) 165 °C Storage Temperature Tstg –65 to 165 °C Rating Unit 2400 VRMS Isolation Characteristics Characteristic Symbol Notes VISO Agency type-tested for 60 seconds per UL standard 60950-1 (edition 2); production-tested at V_ISO for 1 second, in accordance with UL 60950-1 (edition 2). VWVBI Maximum approved working voltage for basic (single) isolation according to UL 60950-1 (edition 2) Clearance Dcl Creepage Dcr Dielectric Strength Test Voltage Working Voltage for Basic Isolation 420 Vpk or VDC 297 Vrms Minimum distance through air from IP leads to signal leads. 3.9 mm Minimum distance along package body from IP leads to signal leads. 3.9 mm Thermal Characteristics Characteristic Symbol Test Conditions* Value Units Package Thermal Resistance (Junction to Ambient) RθJA Mounted on the Allegro 85-0740 evaluation board with 800 mm2 of 4 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. 23 ºC/W Package Thermal Resistance (Junction to Lead) RθJL Mounted on the Allegro ASEK724 evaluation board. 5 ºC/W *Additional thermal information available on the Allegro website. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 3 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 VCC VCC Master Current Supply To All Subcircuits Programming Control POR Hall Current Drive Temperature Sensor CBYPASS 0.1 µF EEPROM and Control Logic Offset Control IP+ Sensitivity Control Dynamic Offset Cancellation IP+ IP– + – RF(int) + – VIOUT IP– GND CF FILTER Functional Block Diagram Pin-Out Diagram and Terminal List Table Terminal List Table IP+ 1 8 VCC IP+ 2 7 VIOUT IP– 3 6 FILTER IP– 4 5 GND Package LC, 8-Pin SOICN Pin-Out Diagram Number Name 1, 2 IP+ Description Terminals for current being sensed; fused internally 3, 4 IP– 5 GND Terminals for current being sensed; fused internally 6 FILTER Terminal for external capacitor that sets bandwidth 7 VIOUT Analog output signal 8 VCC Signal ground terminal Device power supply terminal Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 4 ACS724 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package COMMON ELECTRICAL CHARACTERISTICS1: valid through the full range of TA , VCC = 5 V, CF = 0, unless otherwise specified Characteristic Symbol Test Conditions Min. Typ. Max. Unit 4.5 – 5.5 V – 10 14 mA Supply Voltage VCC Supply Current ICC VCC = 5 V, output open Output Capacitance Load CL VIOUT to GND – – 10 nF Output Resistive Load RL VIOUT to GND 4.7 – – kΩ RIP TA = 25°C – 1.2 – mΩ – 1.8 – kΩ Primary Conductor Resistance Internal Filter Resistance2 Primary Hall Coupling Factor Secondary Hall Coupling Factor Hall Plate Sensitivity Matching RF(int) G1 TA = 25ºC – 11 – G/A G2 TA = 25ºC – 2.8 – G/A Sensmatch TA = 25ºC – ±1 – % Rise Time tr IP = IP(max), TA = 25°C, CL = 1 nF – 3 – μs Propagation Delay tpd IP = IP(max), TA = 25°C, CL = 1 nF – 2 – μs Response Time tRESPONSE IP = IP(max), TA = 25°C, CL = 1 nF – 4 – μs Bandwidth BW Small signal –3 dB; CL = 1 nF – 120 – kHz Noise Density IND Input-referenced noise density; TA = 25°C, CL = 1 nF – 150 – µA(rms)/ √Hz Noise IN Input-referenced noise: CF = 4.7 nF, CL = 1 nF, BW = 18 kHz, TA = 25°C – 20 – mA(rms) –1.5 – +1.5 % Nonlinearity ELIN Through full range of IP Sensitivity Ratiometry Coefficient SENS_RAT_ COEF VCC = 4.5 to 5.5 V, TA = 25ºC – 1.3 – – Zero-Current Output Ratiometry Coefficient QVO_RAT_ COEF VCC = 4.5 to 5.5 V, TA = 25ºC – 1 – – VOH RL = 4.7 kΩ – VCC – 0.3 – V VOL RL = 4.7 kΩ – 0.3 – V tPO Output reaches 90% of steady-state level, TA = 25°C, IP = IPR(max) applied – 80 – μs Saturation Voltage3 Power-On Time Shorted Output-to-Ground Current ISC(GND) TA = 25ºC – 3.3 – mA Shorted Output-to-VCC Current ISC(VCC) TA = 25ºC – 45 – mA 1Device may be operated at higher primary current levels, IP , ambient temperatures, TA , and internal leadframe temperatures, provided the Maximum Junction Temperature, TJ(max), is not exceeded. 2R F(int) forms an RC circuit via the FILTER pin. 3The sensor IC will continue to respond to current beyond the range of I until the high or low saturation voltage; however, the nonlinearity in this region will be worse than P through the rest of the measurement range. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 5 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 xLLCTR-10AU PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 5 V, unless other- wise specified Characteristic Symbol Test Conditions Min. Typ.1 Max. Unit Nominal Performance Current-Sensing Range Sensitivity Zero-Current Output Voltage IPR Sens VIOUT(Q) 0 – 10 A IPR(min) < IP < IPR(max) – 400 – mV/A Unidirectional, IP = 0 A – VCC × 0.1 – V IP = IPR(max), TA = 25°C to 150ºC –2.5 ±1.5 2.5 % IP = IPR(max), TA = –40°C to 25ºC –6 ±4.5 6 % IP = IPR(max), TA = 25°C to 150°C –2 ±1 2 % Accuracy Performance Total Output Error2 ETOT Total Output Error Components3 ETOT = ESENS + 100 × VOE/(Sens × IP) Sensitivity Error Offset Voltage Esens VOE IP = IPR(max), TA = –40°C to 25°C –5.5 ±4.5 5.5 % IP = 0 A, TA = 25°C to 150ºC –15 ±7 15 mV IP = 0 A, TA = –40°C to 25ºC –30 ±13 30 mV Lifetime Drift Characteristics Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 % Total Output Error Lifetime Drift Etot_drift –3 ±1 3 % 1 Typical values with +/- are 3 sigma values 2 Percentage of I , with I = I P P PR(max). 3 A single part will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output error specification. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 6 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 xLLCTR-10AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 5 V, unless other- wise specified Characteristic Symbol Test Conditions Min. Typ.1 Max. Unit Nominal Performance Current-Sensing Range IPR –10 – 10 A Sens IPR(min) < IP < IPR(max) – 200 – mV/A VIOUT(Q) Bidirectional, IP = 0 A – VCC × 0.5 – V IP = IPR(max), TA = 25°C to 150ºC -2 ±1 2 % IP = IPR(max), TA = –40°C to 25ºC -6 ±4.5 6 % IP = IPR(max), TA = 25°C to 150°C -1.5 ±1 1.5 % Sensitivity Zero-Current Output Voltage Accuracy Performance Total Output Error2 Total Output Error ETOT Components3 Sensitivity Error Offset Voltage ETOT = ESENS + 100 × VOE/(Sens × IP) Esens VOE IP = IPR(max), TA = –40°C to 25°C -5.5 ±4.5 5.5 % IP = 0 A, TA = 25°C to 150ºC -10 ±6 10 mV IP = 0 A, TA = –40°C to 25ºC -30 ±8 30 mV Lifetime Drift Characteristics Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 % Total Output Error Lifetime Drift Etot_drift –3 ±1 3 % 1 Typical values with +/- are 3 sigma values 2 Percentage of I , with I = I P P PR(max). 3 A single part will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output error specification. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 7 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 xLLCTR-20AU PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 5 V, unless other- wise specified Characteristic Symbol Test Conditions Min. Typ.1 Max. Unit Nominal Performance Current-Sensing Range IPR Sensitivity Sens Zero-Current Output Voltage VIOUT(Q) 0 – 20 A IPR(min) < IP < IPR(max) – 200 – mV/A Unidirectional, IP = 0 A – VCC × 0.1 – V IP = IPR(max), TA = 25°C to 150ºC -2 ±0.7 2 % IP = IPR(max), TA = –40°C to 25ºC -6 ±4 6 % IP = IPR(max), TA = 25°C to 150°C -1.5 ±0.7 1.5 % Accuracy Performance Total Output Error2 Total Output Error ETOT Components3 Sensitivity Error Offset Voltage ETOT = ESENS + 100 × VOE/(Sens × IP) Esens VOE IP = IPR(max), TA = –40°C to 25°C -5.5 ±4 5.5 % IP = 0 A, TA = 25°C to 150ºC -10 ±6 10 mV IP = 0 A, TA = –40°C to 25ºC -30 ±8 30 mV Lifetime Drift Characteristics Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 % Total Output Error Lifetime Drift Etot_drift –3 ±1 3 % 1 Typical values with +/- are 3 sigma values 2 Percentage of I , with I = I P P PR(max). 3 A single part will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output error specification. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 8 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 xLLCTR-20AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 5 V, unless other- wise specified Characteristic Symbol Test Conditions Min. Typ.1 Max. Unit Nominal Performance Current-Sensing Range IPR –20 – 20 A Sens IPR(min) < IP < IPR(max) – 100 – mV/A VIOUT(Q) Bidirectional, IP = 0 A – VCC × 0.5 – V IP = IPR(max), TA = 25°C to 150ºC -2 ±0.8 2 % IP = IPR(max), TA = –40°C to 25ºC -6 ±4 6 % IP = IPR(max), TA = 25°C to 150°C -1.5 ±0.6 1.5 % Sensitivity Zero-Current Output Voltage Accuracy Performance Total Output Error2 Total Output Error ETOT Components3 Sensitivity Error Offset Voltage ETOT = ESENS + 100 × VOE/(Sens × IP) Esens VOE IP = IPR(max), TA = –40°C to 25°C -5.5 ±4 5.5 % IP = 0 A, TA = 25°C to 150ºC -10 ±5 10 mV IP = 0 A, TA = –40°C to 25ºC -30 ±6 30 mV Lifetime Drift Characteristics Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 % Total Output Error Lifetime Drift Etot_drift –3 ±1 3 % 1 Typical values with +/- are 3 sigma values 2 Percentage of I , with I = I P P PR(max). 3 A single part will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output error specification. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 9 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 xLLCTR-30AU PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 5 V, unless other- wise specified Characteristic Symbol Test Conditions Min. Typ.1 Max. Unit Nominal Performance Current-Sensing Range IPR Sensitivity Sens Zero-Current Output Voltage VIOUT(Q) 0 – 30 A IPR(min) < IP < IPR(max) – 133 – mV/A Unidirectional, IP = 0 A – VCC × 0.1 – V IP = IPR(max), TA = 25°C to 150ºC -2 ±0.7 2 % IP = IPR(max), TA = –40°C to 25ºC -6 ±4 6 % IP = IPR(max), TA = 25°C to 150°C -1.5 ±0.7 1.5 % Accuracy Performance Total Output Error2 Total Output Error ETOT Components3 Sensitivity Error Offset Voltage ETOT = ESENS + 100 × VOE/(Sens × IP) Esens VOE IP = IPR(max), TA = –40°C to 25°C -5.5 ±4 5.5 % IP = 0 A, TA = 25°C to 150ºC -10 ±6 10 mV IP = 0 A, TA = –40°C to 25ºC -30 ±7 30 mV Lifetime Drift Characteristics Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 % Total Output Error Lifetime Drift Etot_drift –3 ±1 3 % 1 Typical values with +/- are 3 sigma values 2 Percentage of I , with I = I P P PR(max). 3 A single part will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output error specification. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 10 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 xLLCTR-30AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 5 V, unless other- wise specified Characteristic Symbol Test Conditions Min. Typ.1 Max. Unit Nominal Performance Current-Sensing Range IPR –30 – 30 A Sens IPR(min) < IP < IPR(max) – 66 – mV/A VIOUT(Q) Bidirectional, IP = 0 A – VCC × 0.5 – V IP = IPR(max), TA = 25°C to 150ºC -2 ±0.8 2 % IP = IPR(max), TA = –40°C to 25ºC -6 ±4 6 % IP = IPR(max), TA = 25°C to 150°C -1.5 ±0.8 1.5 % Sensitivity Zero-Current Output Voltage Accuracy Performance Total Output Error2 Total Output Error ETOT Components3 Sensitivity Error Offset Voltage ETOT = ESENS + 100 × VOE/(Sens × IP) Esens VOE IP = IPR(max), TA = –40°C to 25°C -5.5 ±4 5.5 % IP = 0 A, TA = 25°C to 150ºC -10 ±6 10 mV IP = 0 A, TA = –40°C to 25ºC -30 ±6 30 mV Lifetime Drift Characteristics Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 % Total Output Error Lifetime Drift Etot_drift –3 ±1 3 % 1 Typical values with +/- are 3 sigma values 2 Percentage of I , with I = I P P PR(max). 3 A single part will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output error specification. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 11 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 xLLCTR-50AB PERFORMANCE CHARACTERISTICS: TA Range L, valid at TA = – 40°C to 150°C, VCC = 5 V, CF = 0, unless otherwise specified Characteristic Symbol Test Conditions Min. Typ.1 Max. Unit Nominal Performance Current-Sensing Range IPR –50 – 50 A Sens IPR(min) < IP < IPR(max) – 40 – mV/A VIOUT(Q) Bidirectional, IP = 0 A – VCC × 0.5 – V IP = IPR(max), TA = 25°C to 150ºC -2 ±0.8 2 % IP = IPR(max), TA = –40°C to 25ºC -6 ±4 6 % IP = IPR(max), TA = 25°C to 150°C -1.5 ±0.8 1.5 % Sensitivity Zero-Current Output Voltage Accuracy Performance Total Output Error2 Total Output Error ETOT Components3 Sensitivity Error Offset Voltage ETOT = ESENS + 100 × VOE/(Sens × IP) Esens VOE IP = IPR(max), TA = –40°C to 25°C -5.5 ±4 5.5 % IP = 0 A, TA = 25°C to 150ºC -10 ±6 10 mV IP = 0 A, TA = –40°C to 25ºC -30 ±6 30 mV Lifetime Drift Characteristics Sensitivity Error Lifetime Drift Esens_drift –3 ±1 3 % Total Output Error Lifetime Drift Etot_drift –3 ±1 3 % 1 Typical values with +/- are 3 sigma values 2 Percentage of I , with I = I P P PR(max). 3 A single part will not have both the maximum/minimum sensitivity error and maximum/minimum offset voltage, as that would violate the maximum/minimum total output error specification. Also, 3 sigma distribution values are combined by taking the square root of the sum of the squares. See Application Information section. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 12 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 CHARACTERISTIC PERFORMANCE xLLCTR-10AU Offset Voltage vs. Temperature 515 15 510 10 Offset Voltage (mV) VIOUT(Q) (mV) Zero Current Output Voltage vs. Temperature 505 500 495 490 5 0 -5 -10 485 -15 -50 0 50 100 150 -50 0 Temperature (ºC) 415 4 410 3 405 400 395 390 385 1 0 -1 -2 -3 -4 -5 375 -6 50 100 150 -50 0 Temperature (ºC) 50 100 150 Temperature (ºC) Nonlinearity vs. Temperature Total Error at IPR(max) vs. Temperature 1.00 4 0.80 3 0.60 2 0.40 1 Total Error (%) Nonlinearity (%) 150 2 380 0 100 Sensitivity Error vs. Temperature Sensitivity Error (%) Sensitivity (mV/A) Sensitivity vs. Temperature -50 50 Temperature (ºC) 0.20 0.00 -0.20 -0.40 0 -1 -2 -3 -0.60 -4 -0.80 -5 -6 -1.00 -50 0 50 100 150 -50 Temperature (ºC) +3 Sigma 0 50 100 150 Temperature (ºC) Average -3 Sigma Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 13 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 xLLCTR-10AB Offset Voltage vs. Temperature 2510 10 2508 8 2506 6 Offset Voltage (mV) VIOUT(Q) (mV) Zero Current Output Voltage vs. Temperature 2504 2502 2500 2498 2496 4 2 0 -2 -4 2494 -6 2492 -8 -50 0 50 100 150 -50 0 Temperature (ºC) 100 150 Sensitivity Error vs. Temperature 210 5 208 4 206 3 Sensitivity Error (%) Sensitivity (mV/A) Sensitivity vs. Temperature 204 202 200 198 196 193 192 2 1 0 -1 -2 -3 -4 190 -5 188 -6 -50 0 50 100 150 -50 0 Temperature (ºC) 50 100 150 Temperature (ºC) Nonlinearity vs. Temperature Total Error at IPR(max) vs. Temperature 1.00 5 0.80 4 0.60 3 0.40 2 Total Error (%) Nonlinearity (%) 50 Temperature (ºC) 0.20 0.00 -0.20 -0.40 -0.60 1 0 -1 -2 -3 -4 -0.80 -5 -1.00 -6 -50 0 50 100 -50 150 Temperature (ºC) +3 Sigma 0 50 100 150 Temperature (ºC) Average -3 Sigma Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 14 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 xLLCTR-20AU Offset Voltage vs. Temperature 508 8 506 6 504 4 Offset Voltage (mV) VIOUT(Q) (mV) Zero Current Output Voltage vs. Temperature 502 500 498 496 494 2 0 -2 -4 -6 492 -8 490 -10 -50 0 50 100 150 -50 0 Temperature (ºC) 100 150 Sensitivity Error vs. Temperature 208 4 206 3 204 2 Sensitivity Error (%) Sensitivity (mV/A) Sensitivity vs. Temperature 202 200 198 196 194 192 1 0 -1 -2 -3 -4 190 -5 -50 0 50 100 -50 150 0 Temperature (ºC) 50 100 150 Temperature (ºC) Nonlinearity vs. Temperature Total Error at IPR(max) vs. Temperature 1.00 4 0.80 3 0.60 2 0.40 Total Error (%) Nonlinearity (%) 50 Temperature (ºC) 0.20 0.00 -0.20 -0.40 1 0 -1 -2 -0.60 -3 -0.80 -4 -1.00 -5 -50 0 50 100 -50 150 Temperature (ºC) +3 Sigma 0 50 100 150 Temperature (ºC) Average -3 Sigma Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 15 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 xLLCTR-20AB Offset Voltage vs. Temperature Zero Current Output Voltage vs. Temperature 10 2508 8 Offset Voltage (mV) 2510 VIOUT(Q) (mV) 2506 2504 2502 2500 2498 4 2 0 -2 -4 2496 2494 -50 6 -6 0 50 100 150 -50 0 Temperature (ºC) 104 4 103 3 102 2 Sensitivity Error (%) Sensitivity (mV/A) 100 150 Sensitivity Error vs. Temperature Sensitivity vs. Temperature 101 100 99 98 97 1 0 -1 -2 -3 -4 96 -5 95 -50 0 50 100 -50 150 0 50 100 150 Temperature (ºC) Temperature (ºC) Nonlinearity vs. Temperature Total Error at IPR(max) vs. Temperature 1.00 4 0.80 3 0.60 2 0.40 Total Error (%) Nonlinearity (%) 50 Temperature (ºC) 0.20 0.00 -0.20 -0.40 1 0 -1 -2 -0.60 -3 -0.80 -4 -1.00 -5 -50 0 50 100 -50 150 Temperature (ºC) +3 Sigma 0 50 100 150 Temperature (ºC) Average -3 Sigma Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 16 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 xLLCTR-30AU Offset Voltage vs. Temperature Zero Current Output Voltage vs. Temperature 8 506 6 Offset Voltage (mV) 508 VIOUT(Q) (mV) 504 502 500 498 496 4 2 0 -2 -4 494 -6 492 -8 -50 0 50 100 150 -50 0 Temperature (ºC) 50 100 150 Temperature (ºC) Sensitivity vs. Temperature Sensitivity Error vs. Temperature 4 138 3 Sensitivity Error (%) Sensitivity (mV/A) 136 134 132 130 2 1 0 -1 -2 -3 128 -4 126 -5 -50 0 50 100 -50 150 0 Temperature (ºC) Nonlinearity vs. Temperature 100 150 Total Error at IPR(max) vs. Temperature 1.00 4 0.80 3 0.60 2 0.40 Total Error (%) Nonlinearity (%) 50 Temperature (ºC) 0.20 0.00 -0.20 -0.40 1 0 -1 -2 -0.60 -3 -0.80 -4 -1.00 -5 -50 0 50 100 -50 150 Temperature (ºC) +3 Sigma 0 50 100 150 Temperature (ºC) Average -3 Sigma Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 17 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 xLLCTR-30AB Offset Voltage vs. Temperature 2510 10 2508 8 2506 6 Offset Voltage (mV) VIOUT(Q) (mV) Zero Current Output Voltage vs. Temperature 2504 2502 2500 2498 2496 4 2 0 -2 -4 2494 -6 2492 -50 -8 0 50 100 150 -50 0 Temperature (ºC) Sensitivity vs. Temperature 150 4 3 Sensitivity Error (%) 68 Sensitivity (mV/A) 100 Sensitivity Error vs. Temperature 69 67 66 65 64 63 2 1 0 -1 -2 -3 -4 62 -5 -50 0 50 100 -50 150 0 Temperature (ºC) 50 100 150 Temperature (ºC) Total Error at IPR(max) vs. Temperature Nonlinearity vs. Temperature 1.00 4 0.80 3 0.60 2 0.40 Total Error (%) Nonlinearity (%) 50 Temperature (ºC) 0.20 0.00 -0.20 -0.40 1 0 -1 -2 -3 -0.60 -4 -0.80 -5 -1.00 -50 0 50 100 -50 150 50 100 150 Temperature (ºC) Temperature (ºC) +3 Sigma 0 Average -3 Sigma Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 18 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 APPLICATION INFORMATION Estimating Total Error vs. Sensed Current Here, ESENS and VOE are the ±3 sigma values for those error terms. If there is an average sensitivity error or average offset voltage, then the average Total Error is estimated as: The Performance Characteristics tables give distribution (±3 sigma) values for Total Error at IPR(max); however, one often wants to know what error to expect at a particular current. This can be estimated by using the distribution data for the components of Total Error, Sensitivity Error, and Offset Voltage. The ±3 sigma value for Total Error (ETOT) as a function of the sensed current (IP) is estimated as: 2 Total Error (% of Current Measured) ETOT (IP) = ESENS + ( 100 × VOE Sens × IP ETOTAVG (IP) = ESENSAVG + 100 × VOEAVG Sens × IP The resulting total error will be a sum of ETOT and ETOT_AVG. Using these equations and the 3 sigma distributions for Sensitivity Error and Offset Voltage, the Total Error versus sensed current (IP) is below for the ACS724LLCTR-20AB. As expected, as one goes towards zero current, the error in percent goes towards infinity due to division by zero. 2 ) 8 6 -40ºC + 3σ 4 -40ºC – 3σ 2 25ºC + 3σ 0 25ºC – 3σ -2 85ºC + 3σ -4 85ºC – 3σ -6 -8 0 5 10 15 20 Current (A) Figure 1: Predicted Total Error as a Function of the Sensed Current for the ACS724LLCTR-20AB Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 19 ACS724 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package DEFINITIONS OF ACCURACY CHARACTERISTICS Sensitivity (Sens). The change in sensor IC output in response to a 1 A change through the primary conductor. The sensitivity is the product of the magnetic circuit sensitivity (G / A) (1 G = 0.1 mT) 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. Nonlinearity (ELIN). The nonlinearity is a measure of how linear the output of the sensor IC is over the full current measurement range. The nonlinearity is calculated as: VIOUT(IPR(max)) – VIOUT(Q) ELIN = 1– • 100(%) 2 • VIOUT(IPR(max)/2) – VIOUT(Q) Increasing VIOUT (V) Accuracy at 25°C Only IPR(min) ETOT (IP) = +IP (A) VIOUT(Q) –IP (A) Full Scale IP IPR(max) 0A Accuracy at 25°C Only Decreasing VIOUT (V) Accuracy Across Temperature Figure 1: Output Voltage versus Sensed Current +ETOT Offset Voltage (VOE). The deviation of the device output from its ideal quiescent value of 0.5 × VCC (bidirectional) or 0.1 × VCC (unidirectional) due to nonmagnetic causes. To convert this voltage to amperes, divide by the device sensitivity, Sens. Total Output Error (ETOT). The difference between the current measurement from the sensor IC and the actual current (IP), relative to the actual current. This is equivalent to the difference between the ideal output voltage and the actual output voltage, divided by the ideal sensitivity, relative to the current flowing through the primary conduction path: Accuracy at 25°C Only Ideal VIOUT Accuracy Across Temperature where VIOUT(IPR(max)) is the output of the sensor IC with the maximum measurement current flowing through it and VIOUT(IPR(max)/2) is the output of the sensor IC with half of the maximum measurement current flowing through it. Zero-Current Output Voltage (VIOUT(Q)). The output of the sensor when the primary current is zero. For a unipolar supply voltage, it nominally remains at 0.5 × VCC for a bidirectional device and 0.1 × VCC for a unidirectional device. For example, in the case of a bidirectional output device, VCC = 5 V translates into VIOUT(Q) = 2.5 V. Variation in VIOUT(Q) can be attributed to the resolution of the Allegro linear IC quiescent voltage trim and thermal drift. Accuracy Across Temperature Across Temperature 25°C Only –IP +IP VIOUT_ideal(IP) – VIOUT (IP) • 100 (%) Sensideal(IP) • IP The Total Output Error incorporates all sources of error and is a function of IP . At relatively high currents, ETOT will be mostly due to sensitivity error, and at relatively low currents, ETOT will be mostly due to Offset Voltage (VOE ). In fact, at IP = 0, ETOT approaches infinity due to the offset. This is illustrated in Figures 1 and 2. Figure 1 shows a distribution of output voltages versus IP at 25°C and across temperature. Figure 2 shows the corresponding ETOT versus IP . –ETOT Figure 2: Total Output Error versus Sensed Current Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 20 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 Sensitivity Ratiometry Coefficient (SENS_RAT_COEF). The coefficient defining how the sensitivity scales with VCC. The ideal coefficient is 1, meaning the sensitivity scales proportionally with VCC. A 10% increase in VCC results in a 10% increase in sensitivity. A coefficient of 1.1 means that the sensitivity increases by 10% more than the ideal proportionality case. This means that a 10% increase in VCC results in an 11% increase in sensitivity. This relationship is described by the following equation: Sens(VCC ) = Sens(5 V) 1+ (VCC – 5 V) • SENS_RAT_COEF 5V This can be rearranged to define the sensitivity ratiometry coefficient as: SENS_RAT_COEF = Sens(VCC ) 5V –1 • (VCC – 5 V) Sens(5 V) Zero-Current Output Ratiometry Coefficient (QVO_RAT_ COEF). The coefficient defining how the zero-current output voltage scales with VCC. The ideal coefficient is 1, meaning the output voltage scales proportionally with VCC, always being equal to VCC/2. A coefficient of 1.1 means that the zero-current output voltage increases by 10% more than the ideal proportionality case. This means that a 10% increase in VCC results in an 11% increase in the zero-current output voltage. This relationship is described by the following equation: VIOUTQ(VCC ) = VIOUTQ(5 V) 1+ (VCC – 5 V) • QVO_RAT_COEF 5V This can be rearranged to define the zero-current output ratiometry coefficient as: QVO_RAT_COEF = VIOUTQ(VCC ) 5V –1 • (VCC – 5 V) VIOUTQ(5 V) Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 21 ACS724 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package 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. V VCC VCC(typ.) VIOUT 90% VIOUT VCC(min.) t1 t2 tPO t1= time at which power supply reaches minimum specified operating voltage t2= time at which output voltage settles within ±10% of its steady state value under an applied magnetic field 0 Rise Time (tr). The time interval between a) when the sensor IC 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 IC, in which ƒ(–3 dB) = 0.35 / tr. Both tr and tRESPONSE are detrimentally affected by eddy-current losses observed in the conductive IC ground plane. Propagation Delay (tpd ). The propagation delay is measured as the time interval a) when the primary current signal reaches 20% of its final value, and b) when the device reaches 20% of its output corresponding to the applied current. (%) 90 Figure 3: Power-On Time (tPO) t Primary Current VIOUT Rise Time, tr 20 10 0 Propagation Delay, tpd t Figure 4: Rise Time (tr) and Propagation Delay (tpd) Response Time (tRESPONSE). The time interval between a) when the primary current signal reaches 90% of its final value, and b) when the device reaches 90% of its output corresponding to the applied current. (%) 90 Primary Current VIOUT Response Time, tRESPONSE 0 Figure 5: Response Time (tRESPONSE) Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com t 22 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package ACS724 PACKAGE OUTLING DRAWING For Reference Only – Not for Tooling Use (Reference MS-012AA) Dimensions in millimeters – NOT TO SCALE Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown 8° 0° 4.90 ±0.10 1.27 0.65 8 8 0.25 0.17 3.90 ±0.10 5.60 6.00 ±0.20 A 1.04 REF 1 1.75 2 1 1.27 0.40 C 2 PCB Layout Reference View 0.25 BSC SEATING PLANE Branded Face GAUGE PLANE C 8X 0.10 1.75 MAX C NNNNNNN SEATING PLANE PPT-AAA LLLLL 0.51 0.31 0.25 0.10 1.27 BSC 1 A Terminal #1 mark area B Branding scale and appearance at supplier discretion C 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. B Standard Branding Reference View N = Device part number P = Package Designator T = Device temperature range A = Amperage L = Lot number Belly Brand = Country of Origin Figure 6: Package LC, 8-pin SOICN Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 23 ACS724 Automotive-Grade, Galvanically Isolated Current Sensor IC With Common-Mode Field Rejection in a Small-Footprint SOIC8 Package Document Revision History Revision Pages Responsible Date – Added Characteristic Performance graphs and Application Information to Preliminary draft to create Final draft Change All A. Latham January 16, 2015 1 Corrected Features and Benefits 2 A. Latham June 19, 2015 2 Added ACS724LLCTR-50AB-T variant with electrical characteristics 2, 9 A. Latham June 23, 2015 3 Corrected Characteristic Performance graph legends; updated Lifetime Drift Characteristics and added Error Over Lifetime electrical characteristics 6-18 A. Latham, S. Milano August 12, 2015 Copyright ©2011-2015, Allegro MicroSystems, LLC Allegro MicroSystems, LLC 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 any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, LLC assumes no responsibility for its use; nor for any infringement of patents or other rights of third parties which may result from its use. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 24