FHS AH 600

Integrated Current Sensor FHS AH 600 Definition The FHS AH current sensor is LEM new SMD open loop current sensor based on the Hall effect principle. It benefits from improvement in sensitivity and accuracy temperature stress compensation. It is suitable for DC, AC, pulsed and mixed current measurements. This field sensor has built in Integrated Magnetic Circuit (IMC), that gives an optimum sensitivity, to offer flexibility in compact design without requiring external magnetic core concentrator. It is a perfect solution to measure current flowing in a conductor such as a PCB track. High isolation between the primary circuit and transducer electronics can be obtained with a double-sided PCB. Main features & Advantages Typical applications • • • • • • • • • • • • • • • • • • • Hall effect current sensor with Integrated Magnetic Concentrator (IMC) Magnetic field measurement range ±3.3 mT Supply voltage 5 V Low power consumption High bandwidth: 160 kHz Sensitivity range up over to 200 mV/A Isolated current measurement Small footprint with standard SOIC8 surface mount PCB Low cost, Small size Excellent linearity No power loss in primary circuit Internal reference voltage Small drives BMS Motor control UPS HVAC White goods. PCB track current measurement Standards • AECQ 100 pending Figure 1 FHS AH package – SOIC-8 (Not to scale - For illustration: not representative) Page 1 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Application circuit and pinout Figure 2 Application circuit External circuit example Min Typ Max Unit CSupply 47 100 nF COUT 4.7 6 nF CREF 47 nF R I_OCD 4.7 50 kΩ R E_OCD 4.7 50 kΩ RE 100 kΩ R E REF 100 kΩ CSupply, COUT and CREF should be mounted as close as to the pins. Ideally, R E REF + R E should have a value around 200 kΩ due to current limitation on UREF. UOUT - UREF is positive when primary current flowing under FHS AH from pin 4/5 to the pin 1/8. FHS can be directly mounted above the PCB track in which the current to be measured flows. Pins number Name Description 1 UREF Reference voltage 2 UOUT Output voltage 3 GND Ground terminal 4 UC Supply voltage 5 NC Not Connected or GND 6 OCD EXT External OCD 7 OCD INT Internal OCD 8 UE OCD External OCD threshold voltage terminal Page 2 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Block diagram Figure 3 Block diagram FHS AH Absolute maximum rating Parameter Symbol Unit Min Ambient operating temperature TA °C -40 125 Ambient storage temperature TA st °C -55 165 Maximum junction temperature TJ max °C 165 Output sink current mA -50 Output source current mA 25 Magnetic flux density Bmax T Typ -3 Max Comment TBC 3 Absolute maximum ratings apply at 25 °C unless otherwise noted. Stresses above these ratings may cause permanent damage Exposure to absolute maximum ratings for extended periods may degrade reliability. Environmental and mechanical characteristics Parameter Maximum supply voltage Electrostatic discharge voltage (HBM -Human Body Model) Mass Symbol Unit Value UC max V 8 UESD HBM kV 2 m g 0.08 Page 3 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Electrical Data At TA = 35 °C, UC = +5 V, RL = 100 kΩ, unless otherwise noted (see Min, Max, Typ, definition paragraph in “Terms and definitions” chapter). Parameter Symbol Unit Min Typ Max DC supply voltage UC V 4.5 5 5.5 Current consumption IC mA 12 14 19 Magnetic flux density measuring range BM mT Output voltage in a flux density B Uout V Linearity error 0 … BM εL % of BM Nominal sensitivity SN mV/mT 600 Sensitivity error εS % ±0.5 TCS ppm/K Temperature coefficient of S Lifetime S drift ±3.3 Comment −40 °C ... 125 °C , without RL UC > 4.6 V Uref + UO E + (SN x B) -0.5 0.5 -200 % ±1 200 −40 °C ... 125 °C, referred to 35 °C ±1 TBC Internal reference voltage @ B = 0 T Uref V 2.48 2.5 2.52 Output internal resistance of Uref Rref Ω 120 200 333 −40 °C ... 125 °C TCUref ppm/K -150 150 −40 °C ... 125 °C, referred to 35 °C ±2 TBC Temperature coefficient of Uref Lifetime Uref drift mV Electrical offset UO E mV -10 10 Lifetime UO E drift mV ±2.5 Remanent filed µT 15 After ±BM 0.1 −40 °C ... 125 °C, referred to 35 °C Temperature coefficient of UO E TCUO E mV/K -0.1 Output internal resistance of Uout Rout Ω Noise voltage spectral density Uno µV/Hz1/2 Delay time @ 10 % of BN tD10 µs 1.6 Input signal rise time 2 us Delay time @ 90 % of BN tD90 µs 1.4 Input signal rise time 2 us 160 @ -3 dB Frequency bandwidth BW kHz 100 @ -1 dB 5 DC TBC 17 Overcurrent detection (OCD) Page 4 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Overcurrent detection is a feature included on FHS AH product in order to detect high peaks of currents happening during operation. Two overcurrent detection types are included in this product: Internal OCD and External OCD: Parameter Symbol Unit Min Typ Max Comment Internal OCD Internal OCD detection threshold II OCD Th A TBC ±IPN Internal OCD threshold error ε I OCD Th % ±8 Referred to B @UOUT-UREF=0.8 V Internal OCD output on resistance Ron I OCD  70 95 150 Internal OCD output hold time thold I OCD s 7 10 14 tD I OCD s 1.3 2.1 ±12.5 ±50 Internal OCD delay time Open drain output, active low External OCD External OCD detection threshold IE OCD Th A External OCD threshold error ε E OCD Th % External OCD output on resistance Ron E OCD  External OCD output hold time thold E OCD s 10 tD E OCD s 10 External OCD delay time ±5 35 200 B @UOUT-UREF=0.8 V 280 Open drain output, active low Page 5 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com 𝑈𝐸 𝑂𝐶𝐷 = 𝑅 𝑅𝐸 𝐸 +𝑅𝐸 𝑅𝐸𝐹 ∙ 𝑈𝑅𝐸𝐹 => 𝐵𝐸 𝑂𝐶𝐷 = 𝑈𝑅𝐸𝐹 −𝑈𝐸 𝑂𝐶𝐷 𝑆𝑁 𝑤𝑖𝑡ℎ 0.5 < 𝑈𝐸 𝑂𝐶𝐷 < 𝑈𝑅𝐸𝐹 − 0.5Internal OCD behavior: Figure X Internal OCD behaviour Page 6 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com External OCD behavior: Figure X External OCD behaviour Definition of typical, minimum and maximum values Minimum and maximum values for specified limiting and safety conditions have to be understood as such as well as values shown in “typical” graphs. On the other hand, measured values are part of a statistical distribution that can be specified by an interval with upper and lower limits and a probability for measured values to lie within this interval. Unless otherwise stated (e.g., “100 % tested”), the LEM definition for such intervals designated with “min” and “max” is that the probability for values of samples to lie in this interval is 99.73 %. For a normal (Gaussian) distribution, this corresponds to an interval between −3 sigma and +3 sigma. If “typical” values are not obviously mean or average values, those values are defined to delimit intervals with a probability of 68.27 %, corresponding to an interval between −sigma and +sigma for a normal distribution. Typical, maximal, and minimal values are determined during the initial characterization of the product. Page 7 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Noise Figure X Output voltage noise Linearity Figure X Linearity error @35 °C Figure X Linearity error @125 °C Di/dt Time base: 1 µs/div Primary current UOUT Figure X di/dt Page 8 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Bandwidth Figure X Bandwidth Page 9 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Terms and definitions Sensitivity and linearity To measure sensitivity and linearity, the primary current (DC) is cycled from 0 to BM, then to − BM and back to 0 (equally spaced BM /10 steps). The sensitivity S is defined as the slope of the linear regression line for a cycle between ± BM. The linearity error εL is the maximum positive or negative difference between the measured points and the linear regression line, expressed in % of BM. Delay times The delay time tD 10 @ 10 % and the delay time tD 90 @ 90 % with respect to the primary are shown in the next figure. Both slightly depend on the primary current di/dt. They are measured at nominal voltage output. Figure X tD 10 (delay time @ 10 %) and tD 90 (delay time @ 90 %). Typical connection diagram and ground plane Good EMC practice requires the use of ground planes on PCBs. In drives where high dv/dt transients are present, a ground plane between the primary conductor and FHS AH will reduce or avoid output perturbations due to capacitive currents. However, the ground plane has to be designed to limit eddy currents that would otherwise slow down the response time. The effect of eddy currents is made negligible by cutting the copper plane under the package as shown in bellow figure. Figure X Top side copper plane has a cut under the IC to optimize response time Page 10 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Application information Basic operation: example with a long thin conductor FHS AH is a galvanically isolated current transducer. It senses the magnetic field generated by the measured current and transforms it into an output voltage. If the current is bidirectional, FHS AH will sense the polarity of the magnetic field and generate a positive or negative output voltage relative to the reference voltage. A simple case is presented which illustrates the current to magnetic field and then to output voltage conversion. A current flowing in a long thin conductor generates a flux density around it: 𝐵 𝜇 = 2𝜋0 ∙ 𝐼𝑃 𝑟 (𝑇) With: • • • IP the current to be measured (A) r the distance from the center of the wire (m) μ0 the permeability of vacuum (physical constant, μ0 = 4.π. 10-7 (H/m) Figure X FHS AH orientation to measure the magnetic field generated by a current along a conductor If FHS AH is now placed in the vicinity of the conductor (with its sensitivity direction colinear to the flux density B), it will sense the flux density and the output voltage will be: 𝑈𝑂𝑈𝑇 = 𝐺𝐵 ∙ 𝐵 = 𝐺𝐵 ∙ 𝜇0 𝐼𝑃 𝐼𝑃 ∙ = 1.2 ∙ 10−4 ∙ (𝑉) 2𝜋 𝑟 𝑟 where GB is the FHS AH magnetic sensitivity (600 V/T). The sensitivity is therefore: 𝐺= 𝑈𝑂𝑈𝑇 𝐼𝑃 = 1.2 ∙ 10−4 𝑟 (𝑉/𝐴) The next graph shows how the output voltage decreases when r increases. Note that the sensitivity also depends on the primary conductor shape. Page 11 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Figure X Sensitivity versus the distance between the conductor and the FHS AH sensing elements The example above is of limited practical use as most conductors are not round and thin but explains the principles of FHS AH operation. The measuring range limit (IPM) is reached when the output voltage (UOUT - UREF ) reaches 2 V. This limit is due to electrical saturation of the output amplifier. The input current or field may be increased above this limit without risk for the circuit. Recovery will occur without additional delay (same response time as usual). The maximum current that can be continuously applied to the transducer (IPM) is only limited by the primary conductor carrying capacity. Single track on PCB The main practical configurations will now be reviewed, and their main features highlighted. The use of FHS AH to measure a current flowing in a track provides the following advantages: • • • • Isolation is guaranteed by PCB design. If the primary track is placed on the opposite (bottom) side of the PCB, the isolation can be very high stable and reproducible sensitivity inexpensive large input currents (up to about 100 A). Figure X Principle of FHS AH used to measure current in a PCB track Page 12 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Figure X Sensitivity versus track width and versus distance between the track and the FHS AH sensing elements (TBC) The sensitivity depends on the track width and distance, as shown in above figure. The maximum current that can be safely applied continuously is determined by the temperature rise of the track. The use of a track with varying width gives the best combination of sensitivity and track temperature rise. Multi-turns For low currents (under 10 A), it is advisable to make several turns with the primary track to increase the magnetic field generated by the primary current. Cable or busbar For very large currents (>50A), FHS AH can be used to measure the current flowing in a cable or busbar. The position of FHS AH relatively to the conductor has to be stable to avoid sensitivity variations. Figure X Example with cable or busbar Accuracy considerations Several factors influence the output accuracy of FHS AH as a current transducer: • The sensitivity of the FHS AH • The distance and shape of the primary conductor • The circuit output offset • The circuit non-linearity • Stray fields The sensitivity of the FHS AH is calibrated during production at 600 V/T. As already mentioned, the distance and shape of the primary conductor also influence the sensitivity. No relative movement of the primary conductor to FHS AH should be possible. To avoid differences in a production, the position and shape of the primary conductor and circuit should always be identical. Page 13 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com The magnetic fields generated by neighboring conductors, the earth’s magnetic field, magnets, etc. are also measured if they have a component in the direction to which FHS AH is sensitive (see figure X). As a rule, the stronger the field generated by the primary current, the smaller the influence of stray fields and offset. The primary conductor should therefore be designed to maximize the output voltage. PCB footprint & dimensions (in mm) Figure X SOIC8, Package dimensions Notes: All dimensions are in millimeters (angles in degrees) * Dimensions do not include mold flash, protrusions or gate burrs (shall not exceed 0.15 per side) ** Dimension does not include interleads flash or protrusion (shall not exceed 0.25 per side) *** Dimension does not include dambar protrusion. Allowable dambar protrusion shall be 0.08 mm total in excess of the dimension at maximum material condition. Dambar cannot be located on the lower radius of the foot. Mechanical characteristics Hall plate position Page 14 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Figure X Hall plate position Soldering Recommended reflow soldering profile●●as standard: IPC/JEDEC J-STD-020 revision C Tape and Reel dimensions Page 15 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Packaging Page 16 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Safety ⚠ Caution If the device is used in a way that is not specified by the manufacturer, the protection provided by the device may be compromised. Always inspect the electronics unit and connecting cable before using this product and do not use it if damaged. Mounting assembly shall guarantee the maximum primary conductor temperature, fulfill clearance and creepage distance, minimize electric and magnetic coupling, and unless otherwise specified can be mounted in any orientation. Caution, risk of electrical shock This transducer must be used in limited-energy secondary circuits SELV according to IEC 61010-1, in electric/electronic equipment with respect to applicable standards and safety requirements in accordance with the manufacturer’s operating specifications. Use caution during installation and use of this product; certain parts of the module can carry hazardous voltages and high currents (e.g., power supply, primary conductor). Ignoring this warning can lead to injury and or/or cause serious damage. If applicable: De-energize all circuits and hazardous live parts before installing the product. All installations, maintenance, servicing operations and use must be carried out by trained and qualified personnel practicing applicable safety precautions. This transducer is a build-in device, whose hazardous live parts must be inaccessible after installation. This transducer must be mounted in a suitable end-enclosure. Besides make sure to have minimum 30 mm between the primary terminals of the transducer and other neighboring components. If applicable: Main supply must be able to be disconnected. If applicable: Always inspect the flexible probe for damage before using this product. If applicable: Never connect or disconnect the external power supply while the primary circuit is connected to live parts. If applicable: Never connect the output to any equipment with a common mode voltage to earth greater than 30 V. If applicable: Always wear protective clothing and gloves if hazardous live parts are present in the installation where the measurement is carried out. This transducer is a built-in device, not intended to be cleaned with any product. Nevertheless, if the user must implement cleaning or washing process, validation of the cleaning program has to be done by himself. If applicable: When defining soldering process, please use no cleaning process only. ESD susceptibility The product is susceptible to be damaged from an ESD event and the personnel should be grounded when handling it. Do not dispose of this product as unsorted municipal waste. Contact a qualified recycler for disposal. If CE marking not applicable: Although LEM applies utmost care to facilitate compliance of end products with applicable regulations during LEM product design, use of this part may need additional measures on the application side for compliance with regulations regarding EMC and protection against electric shock. Therefore, LEM cannot be held liable for any potential hazards, damages, injuries or loss of life resulting from the use of this product. Underwriters Laboratory Inc. recognized component Page 17 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com Version history Date Version 2022/01/07 V0 Comment Specimen Page 18 of 18 G21021C SDA/Version 0 N°98.11.11.807.0/Version 0 LEM reserves the right to carry out modifications on its transducers to improve them without prior notice LEM INTERNATIONALE SA Chemin des Aulx 8 1228 PLAN-LES-OUATES SWITZERLAND www.lem.com