Crocus Technology Inc., the leading supplier of disruptive TMR (Tunnel Magneto-Resistance) XtremeSense® sensors, today announced the CT45x family of contactless isolated current sensors to enable high precision and high current measurements in a more simplified solution. Unlike existing solutions, the CT45x allows manufacturers to eliminate costly shields, concentrators or cores. The CT452 and CT453 offers contactless 0.7% accuracy, 1 MHz bandwidth, and better than -50 dB immunity to external magnetic fields without additional mechanical components. This combination of performance and accuracy enables customers to reduce their overall product size and weight which enables them to replace large and costly current sense modules with a small and simple solution.
As current requirements have been increasing so have the challenges of accurately measuring high currents, typically >200 A and often up to 2,000 A. Shunt resistors with isolated amplifiers are broadly used but present an issue with I2R losses and tend to be large and costly. Existing magnetic based solutions like Hall Effect and AMR are less accurate and have high temperature drift. The CT45x products are based on XtremeSense TMR technology that delivers the future with a high signal-to-noise ratio (SNR) contactless approach which can scale with the system requirements, high bandwidth and fast response time, common-model field rejection, combined with high accuracy measurements over temperature.
In addition, many applications now require very accurate current measurements in the milliamp range up to the 1,000 A range or more. Often this type of solution involves multiple current sensors to achieve the desired system performance with many design compromises and complexities. Using Crocus’ XtremeSense TMR current sensors allows for a no-compromise and simple solution using a single CT45x sensor which provides a large dynamic range and a high SNR. For example, the CT45x is able to measure down to 500 mA resolution and up to 1,800 A while maintaining better than 0.7% accuracy.
The CT45x offers groundbreaking noise performance, as low as 0.55 mVRMS, to enable applications to sense small current levels and small changes or variations in current through a busbar. This performance is almost 10 times better than existing Hall Effect solutions. This results in a SNR (signal-to-noise ratio) as high as 77 dB for the CT45x measurement which allows the system to process higher resolution data with higher accuracy.
“With the introduction of the CT45x family of contactless current sense products, we now have a complete portfolio of products for our customers from small currents to larger currents,” states Zack Deiri, President and CEO of Crocus Technology. “This product based on Crocus’ cutting-edge TMR technology is the most exciting for us as the benefits of our XtremeSense TMR are addressing the needs of higher current applications that can’t be met with existing solutions without compromises. Crocus is excited to be addressing new high current markets such as BMS, Inverters, DC/DC Converter and many others.”
Product features and performance:
CT450 & CT452 (5 V version) & CT453 (3.3 V version)
Isolated Contactless Current Sensor
Capable of measuring currents from 5 mA to >2,000 A
Total output error ±0.7% Full-Scale
300 ns response time, 1 MHz bandwidth
Available in six different configured field ranges
Protection capability with Over Field Detection (OFD)
Integrated Common Mode Field Rejection (CMFR) with >90% immunity (CT452/3)
Uniform magnetic field sensing (CT450)
Targeting applications in EV Chargers, Battery Management Systems (BMS), DC/DC Converters, 48-V system, Bidirectional Charging and AC/DC Inverters.
The CT450 is available in TSSOP-8 package. The CT452/3 are available in TSSOP-16 package For more information, please visit the product webpage.