ACS722KMA High Accuracy, Hall-Effect Based Current Sensor IC in High Isolation SOIC16 Package DESCRIPTION FEATURES AND BENEFITS * Patented integrated digital temperature compensation circuitry allows for near closed loop accuracy over temperature in an open loop sensor * UL60950-1 (ed. 2) certified Dielectric Strength Voltage = 4.8 kVrms Basic Isolation Working Voltage = 1097 Vrms Reinforced Isolation Working Voltage = 565 Vrms * Industry-leading noise performance with greatly improved bandwidth through proprietary amplifier and filter design techniques * Pin-selectable band width: 80 kHz for high bandwidth applications or 20 kHz for low noise performance * 0.85 m primary conductor resistance for low power loss and high inrush current withstand capability * Low-profile SOIC16 package suitable for spaceconstrained applications * 3 to 3.6 V, single supply operation * Output voltage proportional to AC or DC current * Factory-trimmed sensitivity and quiescent output voltage for improved accuracy The AllegroTM ACS722 current sensor IC is an economical and precise solution for AC or DC current sensing in industrial, commercial, and communication 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. 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 includes Allegro's patented digital temperature compensation, resulting in extremely accurate performance over temperature. The output of the device has a positive slope when an increasing current flows through the primary copper conduction path (from pins 1 through 4, to pins 5 through 8), which is the path used for current sensing. The internal resistance of this conductive path is 0.85 m typical, providing low power loss. Continued on the next page... pe d Ty ste te TUV America Certificate Number: U8V 16 03 54214 040 CB 16 03 54214 039 The terminals of the conductive path are electrically isolated from the sensor leads (pins 9 through 16). This allows the ACS722 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. CB Certificate Number: US-32210-M1-UL PACKAGE: 16-pin SOICW (suffix MA) Continued on the next page... Not to scale +IP 1 IP+ 2 IP+ 3 IP+ 4 IP+ ACS722 NC GND NC BW_SEL IP VIOUT -IP 5 IP- 6 IP- 7 IP- 8 IP- NC VCC NC 16 15 14 13 12 11 CL 10 9 C BYPASS 0.1 F The ACS722 outputs an analog signal, VIOUT , that changes, proportionally, with the bidirectional AC or DC primary sensed current, IP , within the specified measurement range. The BW_SEL pin can be used to select one of the two bandwidths to optimize the noise performance. Grounding the BW_SEL pin puts the part in the high bandwidth (80 kHz) mode. Typical Application ACS722-DS, Rev 2 MCO-0000540 December 14, 2018 High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package ACS722KMA FEATURES AND BENEFITS (continued) * Chopper stabilization results in extremely stable quiescent output voltage * Nearly zero magnetic hysteresis * Ratiometric output from supply voltage DESCRIPTION (continued) The ACS722 is provided in a low profile surface mount SOIC16 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 hightemperature 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 = 3.3 V (mV/A) ACS722KMATR-10AB-T 10 132 ACS722KMATR-20AB-T 20 66 ACS722KMATR-40AB-T 40 33 [1] Contact Allegro TA (C) Packing [1] -40 to 125 Tape and Reel, 3000 pieces per reel for additional packing options. Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 2 ACS722KMA High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Notes Rating Units Supply Voltage VCC 6 V Reverse Supply Voltage VRCC -0.1 V Output Voltage VIOUT 25 V Reverse Output Voltage VRIOUT -0.1 V Operating Ambient Temperature TA -40 to 125 C Junction Temperature TJ(max) Range K 165 C Storage Temperature Tstg -65 to 165 C ISOLATION CHARACTERISTICS Characteristic Symbol Dielectric Strength Test Voltage VISO Notes Agency type-tested for 60 seconds per UL 60950-1 (edition. 2). Production tested at 3000 VRMS for 1 second, in accordance with UL 60950-1 (edition. 2). Working Voltage for Basic Isolation VWVBI Maximum approved working voltage for basic (single) isolation according UL 60950-1 (edition 2) Working Voltage for Reinforced Isolation VWVRI Maximum approved working voltage for reinforced isolation according to UL 60950-1 (edition 2) Rating Unit 4800 VRMS 1550 VPK 1097 VRMS or VDC 800 VPK 565 VRMS or VDC Clearance Dcl Minimum distance through air from IP leads to signal leads. 7.5 mm Creepage Dcr Minimum distance along package body from IP leads to signal leads 8.2 mm THERMAL CHARACTERISTICS Characteristic Symbol Test Conditions* Value Units mm2 Package Thermal Resistance (Junction to Ambient) RJA Mounted on the Allegro 85-0738 evaluation board with 700 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 C/W Package Thermal Resistance (Junction to Lead) RJL Mounted on the Allegro ASEK 722 evaluation board. 5 C/W *Additional thermal information available on the Allegro website. Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 3 ACS722KMA High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package VCC Master Current Supply To All Subcircuits Programming Control POR Hall Current Drive Temperature Sensor EEPROM and Control Logic Offset Control IP+ IP+ IP+ IP+ Dynamic Offset Cancellation Sensitivity Control IP - IP - IP - IP- Tuned Filter BW_SEL VIOUT GND Functional Block Diagram Terminal List Table IP+ 1 16 NC IP+ 2 15 GND IP+ 3 14 NC IP+ 4 13 BW_SEL IP- 12 VIOUT 5 IP- 6 11 NC IP- 7 10 VCC IP- 8 9 NC Pinout Diagram Number Name Description 1, 2, 3, 4 IP+ Terminals for current being sensed; fused internally 5, 6, 7, 8 IP- Terminals for current being sensed; fused internally 9, 16 NC No internal connection; recommended to be left unconnected in order to maintain high creepage. 10 VCC 11, 14 NC 12 VIOUT 13 BW_SEL 15 GND Device power supply terminal No internal connection; recommened to connect to GND for the best ESD performance Analog output signal Terminal for selecting 20 kHz or 80 kHz bandwidth Signal ground terminal Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 4 ACS722KMA High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package COMMON ELECTRICAL CHARACTERISTICS [1]: Valid through the full range of TA = -40C to 125C , and at VCC = 3.3 V, unless otherwise specified Characteristic Symbol Supply Voltage VCC Supply Current ICC Output Capacitance Load CL Test Conditions Min. Typ. Max. Units 3 3.3 3.6 V VCC within VCC(min) and VCC(max) - 9 12 mA VIOUT to GND - - 10 nF 4.7 - - k - 0.85 - m Output Resistive Load RL VIOUT to GND Primary Conductor Resistance RIP TA = 25C Magnetic Coupling Factor CF Rise Time Propagation Delay Response Time Internal Bandwidth Noise Density Noise Nonlinearity Saturation Voltage [2] Power-On Time tr tpd tRESPONSE BWi IND IN - 4.5 - G/A IP = IP(max), TA = 25C, CL = 1 nF, BW_SEL tied to GND - 4 - s IP = IP(max), TA = 25C, CL = 1 nF, BW_SEL tied to VCC - 17.5 - s IP = IP(max), TA = 25C, CL = 1 nF, BW_SEL tied to GND - 2 - s IP = IP(max), TA = 25C, CL = 1 nF, BW_SEL tied to VCC - 5 - s IP = IP(max), TA = 25C, CL = 1 nF, BW_SEL tied to GND - 5 - s IP = IP(max), TA = 25C, CL = 1 nF, BW_SEL tied to VCC - 22.5 - s Small signal -3 dB; CL = 1 nF, BW_SEL tied to GND - 80 - kHz Small signal -3 dB; CL = 1nF, BW_SEL tied to VCC - 20 - kHz Input referenced noise density; TA = 25C, CL = 1 nF - 300 - A(rms)/ Hz Input referenced noise; BWi = 80 kHz, TA = 25C, CL = 1 nF - 84 - mA(rms) Input referenced noise; BWi = 20 kHz, TA = 25C, CL = 1 nF - 42 - mA(rms) ELIN Through full range of IP - 1 VOH RL = 4.7 k, TA = 25C VCC - 0.33 - - % V VOL RL = 4.7 k, TA = 25C - - 0.33 V tPO Output reaches 90% of steady-state level, TA = 25C, IP = IPR(max) applied - 64 - s [1] Device 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. [2] The 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 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 5 High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package ACS722KMA xKMATR-10AB PERFORMANCE CHARACTERISTICS: TA Range K, valid at TA = - 40C to 125C, VCC = 3.3 V, unless otherwise specified Characteristic Symbol Test Conditions Min. Typ.[1] Max. Units NOMINAL PERFORMANCE Current Sensing Range Sensitivity Zero Current Output Voltage IPR -10 - 10 A Sens IPR(min) < IP < IPR(max) - 132 - mV/A VIOUT(Q) Bidirectional; IP = 0 A - VCC x 0.5 - V IP = IPR(max), TA = 25C to 125C -2.5 1.7 2.5 % IP = IPR(max), TA = -40C to 25C - 2.5 - % TA = 25C to 125C; measured at IP = IPR(max) -2 1.5 2 % TA = -40C to 25C; ; measured at IP = IPR(max) - 2.3 - % ACCURACY PERFORMANCE Total Output Error [2] ETOT TOTAL OUTPUT ERROR COMPONENTS [3]: ETOT = ESENS + 100 x VOE/(Sens x IP) Sensitivity Error ESENS Offset Voltage [4] VOE IP = 0 A; TA = 25C to 125C -15 7 15 mV IP = 0 A; TA = -40C to 25C - 20 - mV Esens_drift - 1 - % Etot_drift - 1 - % LIFETIME DRIFT CHARACTERISTICS Sensitivity Error Lifetime Drift Total Output Error Lifetime Drift Typical values with +/- are 3 sigma values. Percentage of IP , with IP = IPR(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. [4] Offset Voltage does not incorporate any error due to external magnetic fields. See section: Impact of External Magnetic Fields. [1] [2] Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 6 High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package ACS722KMA xKMATR-20AB PERFORMANCE CHARACTERISTICS: TA Range K, valid at TA = - 40C to 125C, VCC = 3.3 V, unless otherwise specified Characteristic Symbol Test Conditions Min. Typ.[1] Max. Units NOMINAL PERFORMANCE Current Sensing Range Sensitivity Zero Current Output Voltage IPR -20 - 20 A Sens IPR(min) < IP < IPR(max) - 66 - mV/A VIOUT(Q) Bidirectional; IP = 0 A - VCC x 0.5 - V IP = IPR(max), TA = 25C to 125C -2 1.2 2 % IP = IPR(max), TA = -40C to 25C - 2.1 - % -1.5 0.75 1.5 % ACCURACY PERFORMANCE Total Output Error [2] ETOT TOTAL OUTPUT ERROR COMPONENTS [3]: ETOT = ESENS + 100 x VOE/(Sens x IP) Sensitivity Error Offset Voltage [4] ESENS TA = 25C to 125C; measured at IP = IPR(max) TA = -40C to 25C; ; measured at IP = IPR(max) - 1.25 - % IP = 0 A; TA = 25C to 125C -10 4.5 10 mV IP = 0 A; TA = -40C to 25C - 10 - mV Esens_drift - 1 - % Etot_drift - 1 - % VOE LIFETIME DRIFT CHARACTERISTICS Sensitivity Error Lifetime Drift Total Output Error Lifetime Drift Typical values with +/- are 3 sigma values. Percentage of IP , with IP = IPR(max) 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. [4] Offset Voltage does not incorporate any error due to external magnetic fields. See section: Impact of External Magnetic Fields. [1] [2] [3] A single Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 7 High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package ACS722KMA xKMATR-40AB PERFORMANCE CHARACTERISTICS: TA Range K, valid at TA = - 40C to 125C, VCC = 3.3 V, unless otherwise specified Characteristic Symbol Test Conditions Min. Typ. [1] Max. Units NOMINAL PERFORMANCE Current Sensing Range Sensitivity Zero Current Output Voltage IPR -40 - 40 A Sens IPR(min) < IP < IPR(max) - 33 - mV/A VIOUT(Q) Bidirectional; IP = 0 A - VCC x 0.5 - V IP = IPR(max), TA = 25C to 125C -2 1.25 2 % IP = IPR(max), TA = -40C to 25C - 2 - % -1.5 1.2 1.5 % ACCURACY PERFORMANCE Total Output Error [2] ETOT TOTAL OUTPUT ERROR COMPONENTS [3]: ETOT = ESENS + 100 x VOE/(Sens x IP) Sensitivity Error Offset Voltage [4] ESENS TA = 25C to 125C; measured at IP = IPR(max) TA = -40C to 25C; ; measured at IP = IPR(max) - 1.75 - % IP = 0 A; TA = 25C to 125C -10 3 10 mV IP = 0 A; TA = -40C to 25C - 5 - mV Esens_drift - 1 - % Etot_drift - 1 - % VOE LIFETIME DRIFT CHARACTERISTICS Sensitivity Error Lifetime Drift Total Output Error Lifetime Drift Typical values with +/- are 3 sigma values. Percentage of IP , with IP = IPR(max) 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. [4] Offset Voltage does not incorporate any error due to external magnetic fields. See section: Impact of External Magnetic Fields. [1] [2] [3] A single Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 8 ACS722KMA High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package CHARACTERISTIC PERFORMANCE xKMATR-10AB Key Parameters Offset Voltage vs. Temperature 1675 25 1670 20 1665 15 Offset Voltage (mV) VIOUT(Q) (mV) Zero Current Output Voltage vs. Temperature 1660 1655 1650 1645 10 5 0 -5 1640 -10 1635 -15 1630 -50 -20 0 50 100 150 -50 0 50 Temperature (C) Sensitivity Error vs. Temperature Sensitivity vs. Temperature 4.00 136 3.00 135 Sensitivity Error (%) Sensitivity (mV/A) 150 Temperature (C) 137 134 133 132 131 2.00 1.00 0.00 -1.00 130 129 -50 100 -2.00 0 50 100 150 -50 0 Temperature (C) 50 100 150 Temperature (C) Total Error at IPR(max) vs. Temperature Nonlinearity vs. Temperature 4.00 2.0 1.5 3.00 Total Error (%) Nonlinearity (%) 1.0 0.5 0.0 -0.5 2.00 1.00 0.00 -1.0 -1.00 -1.5 -2.00 -2.0 -50 0 50 100 150 -50 Temperature (C) 0 50 100 150 Temperature (C) +3 Sigma Average -3 Sigma Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 9 ACS722KMA High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package xKMATR-20AB Key Parameters Offset Voltage vs. Temperature 1665 15 1660 10 Offset Voltage (mV) VIOUT(Q) (mV) Zero Current Output Voltage vs. Temperature 1655 1650 0 -5 1645 1640 -50 5 -10 0 50 100 150 -50 0 50 Temperature (C) 68 2.0 67 Sensitivity Error (%) Sensitivity (mV/A) 2.5 67 66 66 65 1.5 1.0 0.5 0.0 0.5 -1.0 -1.5 65 -2.0 0 50 100 150 -50 0 Temperature (C) 100 150 Total Error at IPR(max) vs. Temperature 1.0 3.0 0.8 2.5 0.6 2.0 0.4 1.5 Total Error (%) Nonlinearity (%) 50 Temperature (C) Nonlinearity vs. Temperature 0.2 0.0 -0.2 -0.4 -0.6 -0.8 1.0 0.5 0.0 -0.5 -1.0 -1.5 -2.0 -1.0 -50 150 Sensitivity Error vs. Temperature Sensitivity vs. Temperature 68 -50 100 Temperature (C) 0 50 100 150 -50 Temperature (C) 0 50 100 150 Temperature (C) +3 Sigma Average -3 Sigma Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 10 ACS722KMA High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package xKMATR-40AB Key Parameters Offset Voltage vs. Temperature 1656 6 1654 4 Offset Voltage (mV) VIOUT(Q) (mV) Zero Current Output Voltage vs. Temperature 1652 1650 1648 1646 0 -2 -4 1644 -50 2 -6 0 50 100 150 -50 0 50 Temperature (C) 100 150 Temperature (C) Sensitivity Error vs. Temperature Sensitivity vs. Temperature 34 2.5 2.0 34 Sensitivity Error (%) Sensitivity (mV/A) 1.5 33 33 33 33 33 32 -50 1.0 0.5 0.0 -0.5 -1.0 -1.5 -2.0 -2.5 0 50 100 150 -50 0 Temperature (C) 2.5 0.8 2.0 0.6 1.5 0.4 1.0 Total Error (%) Nonlinearity (%) 1.0 0.2 0.0 -0.2 -0.4 0.5 -0.5 -1.0 -1.5 -0.8 -1.0 -2.0 -2.5 50 150 0.0 -0.6 0 100 Total Error at IPR(max) vs. Temperature Nonlinearity vs. Temperature -50 50 Temperature (C) 100 150 -50 Temperature (C) 0 50 100 150 Temperature (C) +3 Sigma Average -3 Sigma Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 11 ACS722KMA High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 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 coupling factor (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. 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 25C and across temperature. Figure 2 shows the corresponding ETOT versus IP . Increasing VIOUT (V) 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: { [ ELIN = 1- VIOUT (IPR(max)) - VIOUT(Q) 2 x VIOUT (IPR(max)/2) - VIOUT(Q) [{ Accuracy at 25C Only IPR(min) Full Scale IP Accuracy at 25C Only Decreasing VIOUT (V) Accuracy Across Temperature Figure 1: Output Voltage versus Sensed Current +ETOT The deviation of the device output from its ideal quiescent value of 0.5 x VCC (bidirectional) or 0.1 x VCC (unidirectional) due to nonmagnetic causes. To convert this voltage to amperes, divide by the device sensitivity, Sens. Across Temperature 25C Only Total Output Error (ETOT) The 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: VIOUT_ideal(IP) - VIOUT(IP) Sensideal(IP) x IP IPR(max) 0A Offset Voltage (VOE) ETOT(IP) = +IP (A) VIOUT(Q) -IP (A) 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 x VCC for a bidirectional device and 0.1 x VCC for a unidirectional device. For example, in the case of a bidirectional output device, 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. Accuracy at 25C Only Ideal VIOUT Accuracy Across Temperature x 100 (%) 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. Accuracy Across Temperature x 100 (%) The Total Output Error incorporates all sources of error and is a function of IP . At relatively high currents, ETOT will be mostly -IP +IP -ETOT Figure 2: Total Output Error versus Sensed Current Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 12 ACS722KMA High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package APPLICATION INFORMATION Impact of External Magnetic Fields The ACS722 works by sensing the magnetic field created by the current flowing through the package. However, the sensor cannot differentiate between fields created by the current flow and external magnetic fields. This means that external magnetic fields can cause errors in the output of the sensor. Magnetic fields which are perpendicular to the surface of the package affect the output of the sensor, as it only senses fields in that one plane. The error in Amperes can be quantified as: B CF For example, an external field of 1 Gauss will result in around 0.22 A of error. If the ACS722KMATR-10AB, which has a nominal sensitivity of 132 mV/A, is being used, that equates to 29 mV of error on the output of the sensor. Table 1: External Magnetic Field (Gauss) Impact Error (A) 0.5 0.11 ( Error (mV) 10AB 20AB 40AB 15 7 4 1 0.22 29 15 7 2 0.44 58 29 15 Estimating Total Error vs. Sensed Current The Performance Characteristics tables give distribution (3 sigma) values for Total Error at I_PR(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 2 ) 100 x VOE Sens x IP 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: ETOTAVG (IP) = ESENSAVG + where B is the strength of the external field perpendicular to the surface of the package in Gauss, and CF is the coupling factor in G/A. Then, multiplying by the sensitivity of the part (Sens) gives the error in mV. External Field (Gauss) 2 ETOT(IP) = ESENS + 100 x VOEAVG Sens x 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 vs. sensed current (IP) is below for the ACS722KMATR-40AB. As expected, as one goes towards zero current, the error in percent goes towards infinity due to division by zero (refer to Figure 3) 15.00 Total Error (% of current measured) Error(B) = 3 sigma value for Total Error (ETOT) as a function of the sensed current (IP) is estimated as: 10.00 -40C+3sig 5.00 -40C-3sig 25C+3sig 0.00 25C-3sig 125C+3sig -5.00 125C-3sig -10.00 -15.00 0 5 10 15 20 25 30 35 40 Current (A) Figure 3: Predicted Total Error as a Function of Sensed Current for the ACS722KMATR-40AB Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 13 ACS722KMA High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 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 (refer to Figure 4). V Propagation Delay (tpd ) The propagation delay is measured as the time interval between: 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 (refer to Figure 5). 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 (refer to Figure 6). 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 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 (refer to Figure 5). The rise time to a step response is used to derive the bandwidth of the current sensor IC, 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. VCC VCC(typ.) 0 t Figure 4: Power-On Time (%) 90 Primary Current VIOUT Rise Time, tr 20 10 0 Propagation Delay, tpd t Figure 5: Rise Time and Propagation Delay (%) 90 Primary Current VIOUT Response Time, tRESPONSE 0 t Figure 6: Response Time Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 14 High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package ACS722KMA NOT TO SCALE All dimensions in millimeters. 15.75 9.54 0.65 1.27 Package Outline Slot in PCB to maintain >8 mm creepage once part is on PCB 2.25 7.25 1.27 3.56 17.27 Current Out Current In 21.51 Perimeter holes for stitching to the other, matching current trace design, layers of the PCB for enhanced thermal capability. Figure 7: High-Isolation PCB Layout Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 15 High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package ACS722KMA PACKAGE OUTLINE DRAWING For Reference Only - Not for Tooling Use (Reference MS-013AA) NOT TO SCALE Dimensions in millimeters Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown 8 0 10.30 0.20 16 0.33 0.20 7.50 0.10 10.30 0.33 A 1 1.27 1.40 REF 0.40 2 Branded Face 0.25 BSC SEATING PLANE 16X C 2.65 MAX 0.10 C GAUGE PLANE SEATING PLANE 0.30 0.10 1.27 BSC 0.51 0.31 0.65 1.27 16 NNNNNNN LLLLLLLL 2.25 1 9.50 1 C 2 PCB Layout Reference View B Standard Branding Reference View A Terminal #1 mark area B Branding scale and appearance at supplier discretion N = Device part number L = Assembly Lot Number, first eight characters 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 Figure 8: Package MA, 16-pin SOICW Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 16 ACS722KMA High Accuracy, Hall-effect Based Current Sensor IC in High Isolation SOIC16 Package REVISION HISTORY Number Date - March 4, 2015 1 April 13, 2016 2 December 14, 2018 Description Initial release Corrected Package Outline Drawing branding information (page 16). Updated certificate numbers and minor editorial updates Copyright (c)2018, 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. Copies of this document are considered uncontrolled documents. For the latest version of this document, visit our website: www.allegromicro.com Allegro MicroSystems, LLC 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 17