Fully Integrated / Hall Effect-Based Linear Current Sensor

www.DataSheet4U.com ACS712 Fully Integrated, Hall Effect-Based Linear Current Sensor with 2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ Features and Benefits Low-noise analog signal path Device bandwidth is set via the new FILTER pin 5 µs output rise time in response to step input current 50 kHz bandwidth Total output error 1.5% at TA = 25°C, and 4% at –40°C to 85°C Small footprint, low-profile SOIC8 package 1.2 mΩ internal conductor resistance 2.1 kVRMS minimum isolation voltage from pins 1-4 to pins 5-8 5.0 V, 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 voltage Description The Allegro® ACS712 provides economical and precise solutions for AC or DC current sensing in industrial, automotive, commercial, and communications systems. The device package allows for easy implementation by the customer. 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. Device accuracy is optimized through the close proximity of the magnetic signal 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 (>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 1.2 mΩ typical, providing low power Package: 8 pin SOIC (suffix LC) Approximate Scale 1:1 Continued on the next page… Typical Application 1 2 IP 3 4 IP+ VCC 8 7 VOUT +5 V CBYP 0.1 µF IP+ VIOUT ACS712 IP– FILTER IP– GND 6 5 CF 1 nF Application 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 application. ACS712-DS ACS712 Fully Integrated, Hall Effect-Based Linear Current Sensor with 2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor Description (continued) loss. 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 techniques. Selection Guide Part Number ACS712ELCTR-05B-T ACS712ELCTR-20A-T ACS712ELCTR-30A-T Packing* Tape and reel, 3000 pieces/reel Tape and reel, 3000 pieces/reel Tape and reel, 3000 pieces/reel The ACS712 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. 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. TOP (°C) –40 to 85 –40 to 85 –40 to 85 Optimized Range, IP (A) ±5 ±20 ±30 Sensitivity, Sens (Typ) (mV/A) 185 100 66 *Contact Allegro for additional packing options. Absolute Maximum Ratings Characteristic Supply Voltage Reverse Supply Voltage Output Voltage Reverse Output Voltage Output Current Source Output Current Sink Overcurrent Transient Tolerance Maximum Transient Sensed Current Nominal Operating Ambient Temperature Maximum Junction Storage Temperature Symbol VCC VRCC VIOUT VRIOUT IIOUT(Source) IIOUT(Sink) IP IR(max) TA TJ(max) Tstg 100 total pulses, 250 ms duration each, applied at a rate of 1 pulse every 100 seconds. Junction Temperature, TJ < TJ(max) Range E Notes Rating 8 –0.1 8 –0.1 3 10 60 60 –40 to 85 165 –65 to 170 Units V V V V mA mA A A ºC ºC ºC TÜV America Certificate Number: U8V 06 05 54214 010 Parameter Fire and Electric Shock Specification CAN/CSA-C22.2 No. 60950-1-03 UL 60950-1:2003 EN 60950-1:2001 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 2 ACS712 Fully Integrated, Hall Effect-Based Linear Current Sensor with 2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor Functional Block Diagram +5 V VCC (Pin 8) Hall Current Drive IP+ (Pin 1) Sense Temperature Coefficient Trim Dynamic Offset Cancellation IP+ (Pin 2) Signal Recovery RF(INT) VIOUT (Pin 7) IP– (Pin 3) IP– (Pin 4) Sense Trim 0 Ampere Offset Adjust GND (Pin 5) FILTER (Pin 6) Pin-out Diagram IP+ IP+ IP– IP– 1 2 3 4 8 7 6 5 VCC VIOUT FILTER GND Terminal List Table Number 1 and 2 3 and 4 5 6 7 8 Name IP+ IP– GND FILTER VIOUT VCC Description Terminals for current being sensed; fused internally Terminals for current being sensed; fused internally Signal ground terminal Terminal for external capacitor that sets bandwidth Analog output signal Device power supply terminal Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 3 ACS712 Fully Integrated, Hall Effect-Based Linear Current Sensor with 2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor COMMON OPERATING CHARACTERISTICS1 over full range of TOP , CF = 1 nF, and VCC = 5 V, unless otherwise specified Characteristic Supply Voltage Supply Current Output Zener Clamp Voltage Output Resistance Output Capacitance Load Output Resistive Load Primary Conductor Resistance RMS Isolation Voltage DC Isolation Voltage Propagation Time Response Time Rise Time Frequency Bandwidth Nonlinearity Symmetry Zero Current Output Voltage Magnetic Offset Error Clamping Voltage Symbol VCC ICC VZ RIOUT CLOAD RLOAD RPRIMARY VISORMS VISODC tPROP tr f ELIN ESYM VIOUT(Q) VERROM VCH VCL Power-On Time Magnetic 1Device Test Conditions Min. 4.5 Typ. 5.0 8 8.3 1 – – 1.2 – 5000 3 7 5 – ±1 100 VCC × 0.5 0 Max. 5.5 11 – 2 10 – – – – – – – – ±1.5 102 – – Units V mA V Ω nF kΩ mΩ V V μs μs μs kHz % % V mV mV mV µs G/A kΩ ELECTRICAL CHARACTERISTICS VCC = 5.0 V, output open ICC = 11 mA, TA = 25°C IIOUT = 1.2 mA, TA=25°C VIOUT to GND VIOUT to GND TA = 25°C Pins 1-4 and 5-8; 60 Hz, 1 minute, TA=25°C Pins 1-4 and 5-8; 1 minute, TA=25°C IP = IP(max), TA = 25°C, COUT = open IP = IP(max), TA = 25°C, COUT = open –3 dB, TA = 25°C; IP is 10 A peak-to-peak Over full range of IP Over full range of IP Bidirectional; IP = 0 A, TA = 25°C IP = 0 A, after excursion of 5 A 6 6 – – 4.7 – 2100 – – – – 50 – 98 – – Typ. –110 Typ. –110 Output reaches 90% of steady-state level, TJ = 25°C, 20 A present on leadframe – – RF(INT) tRESPONSE IP = IP(max), TA = 25°C, COUT = open VCC × Typ. +110 0.9375 VCC × Typ. +110 0.0625 35 12 1.7 – – tPO Coupling2 Internal Filter Resistance3 may be operated at higher primary current levels, IP, and ambient, TA , and internal leadframe temperatures, TOP , provided that the Maximum Junction Temperature, TJ(max), is not exceeded. 21G = 0.1 mT. 3R F(INT) forms an RC circuit via the FILTER pin. COMMON THERMAL CHARACTERISTICS1 Min. Operating Internal Leadframe Temperature Junction-to-Lead Thermal Resistance2 Junction-to-Ambient Thermal Resistance 1Additional 2The Allegro Typ. – Max. 85 Value 5 23 Units °C Units °C/W °C/W TOP RθJL RθJA E range Mounted on the Allegro ASEK 712 evaluation board –40 Mounted on the Allegro 85-0322 evaluation board, includes the power consumed by the board thermal information is 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. Further information about board design and thermal performance also can be found in the Applications Information section of this datasheet. Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 4 ACS712 Characteristic Optimized Accuracy Range Sensitivity2 Fully Integrated, Hall Effect-Based Linear Current Sensor with 2.1 kVRMS Voltage Isolation and a Low-Resistance Current Conductor x05A PERFORMANCE CHARACTERISTICS TOP = –40°C to 85°C1, CF = 1 nF, and VCC = 5 V, unless otherwise specified Symbol IP SensTA SensTOP Over full range of IP, TA = 25°C Over full range of IP Peak-to-peak, TA= 25°C, 185 mV/A programmed Sensitivity, CF = 4.7 nF, COUT = open, 20 kHz bandwidth Noise VNOISE(PP) Peak-to-peak, TA = 25°C, 185 mV/A programmed Sensitivity, CF = 47 nF, COUT = open, 2 kHz bandwidth Peak-to-peak, TA = 25°C, 185 mV/A programmed Sensitivity, CF = 1 nF, COUT = open, 50 kHz bandwidth Electrical Offset Voltage Total Output Error3 1Device Test Conditions Min. –5 – 178 – – – –40 – Typ. – 185 – 45 20 75 – ±1.5 Max. 5 – 193 – – – 40 – Units A mV/A mV/A mV mV mV mV % VOE ETOT IP = 0 A IP =±5 A, TA = 25°C may be operated at higher primary current levels, IP, and ambient temperatures, TOP, provided that the Maximum Junction Temperature, TJ(max), is not exceeded. 2