Though lot of applications use simple way of DC current measurement by connecting low resistance shunt resistor in series with the circuit for which current needs to be measured. For measuring AC currents, current Transformers is one of the simple and older option. To achieve electrical isolation, non-intrusiveness, to save space, to save power, unnecessary heat production, increased safety and to expand the range of current measurement, there are new ways of measuring current. Since flowing electric current produces magnetism, the magnetism-based current sensors are the best, reliable, and safe choice. Magnetic base current sensors offer all the above said advantages but when it comes to accuracy only a particular type of magnetic sensors achieve higher accuracy than shunt resistor type current sensing. Here in this article we are providing you some of the reliable and leading magnetic current sensor products for Electric Vehicles(EV) :
1. CFS1000 from Sensitec: This AEC-Q100 qualified automotive grade programmable sensor from Sensitec is based on anisotropic magnetoresistance effect can measure wide DC AC, and pulsed current range of 10 A to 1000 A and bandwidth up to 500 kilo hertz. This compact device packs AMR sensor chip, two bias magnets and a signal conditioning application-specific analog chip. This contactless current sensor features high dynamic response without Hystersis or saturation effect. This device operates from a supply voltage of 5 V and produces the output current of 2 mA with overall current measuring accuracy of +/-1%. This device is designed to operate in ambient temperature range of -40 to +1 25°C.
To know more on this product visit: https://www.sensitec.com/products-solutions/current-measurement/cfs1000
2.The automotives specific Hall effect magnetic sensors MLX91218 and MLX91219 from Melexis can measure current in the range of 200 A to 2000 A. These devices can operate from a supply voltage of either 3.3 V are 5 V and deliver current measuring accuracy of +/-1%. These devices have on chip analog circuitry and also integrate overcurrent detection circuitry in a tiny SOIC8 package. With 400 KHz bandwidth, these low noise, AEC-Q100 automotive-qualified sensors provide selectable analog output that scales with the supply voltage. These sensors as per the suggestion by the company can be used to measure and control current flowing into inverter or converter circuit and also battery charging and discharging management in your electric car, bike and any other vehicle design.
To know further details on MLX91218 and MLX91219 visit: https://www.melexis.com/en/product/MLX91219/400-kHz-Conventional-Hall-Current-Sensor-dual-overcurrent-detection
3. The most recent current sensors from Crocus Technology looks to perform better than others in this list. CT452 and CT453 deliver current measuring accuracy of 0.7% and 1 Megahertz bandwidth to measure current in the range up to 2000 A. Manufacturer of these sensor says, they offer high dynamic range and high signal-to-noise ratio, where they can be used to measure currents down to 500 Ma resolution and up 1800 A while maintaining better than 0.7% accuracy. Crocus claims these sensors offer groundbreaking Noise performance of as low as 0.55 Mvrms, claiming 10 times better than the competing existing solutions. These automotive grade AEC-Q100 Grade 1 qualified current sensors can operate in the temperature range of -40 to +125°C. Available in 16-lead TSSOP package, CT452 and CT453 integrate Over-Field Detection (OFD) circuitry and Under-Voltage Lock-out protection circuitry functions. CT452 operates from a supply voltage of 5 V whereas CT453 operates from a supply voltage of 3.3 V. Suggested applications by the vendor include electric vehicle (EV) chargers, battery management systems , DC/DC Converters, 48-V system, Bidirectional Charging and AC/DC Inverters. Statement in the datasheet says "This coreless current sensor is not only small in size and simple to design but it also provides effective common mode rejection of more than -50 Db. This enables the CT453 to have greater than 90% immunity to stray magnetic fields thus having almost no impact on the accuracy of the current measurement."
To learn more about this product visit: https://crocus-technology.com/wp-content/uploads/2022/05/CT453-Data-Sheet-Rev0.1.pdf
4. TLE4972 from Infineon: TLE4972 suggested for traction inverters used in hybrid and battery-driven vehicles, and battery main switches can measure current ranges up to 2000 A. PG-VSON-6 packaged TLE4972 has two separate output pins for overcurrent detection with a typical response time of less than 1 µs. With drift of sensitivity plus offset over temperature is below 1.6 percent, this sensor is versatile and can be used as redundant solution in 400 V or 800 V battery main switches.
To know more on TLE4972 visit: https://www.infineon.com/cms/en/product/sensor/current-sensors/tle4972-ae35s5/