Crocus Technology Expands High Precision Portfolio of Isolated Current Sensors over Industrial and Automotive Temperature Ranges

The CT425 family of XtremeSense® TMR products offers high accuracy isolated current sensing with Common Mode Field Rejection at 1 MHz bandwidth

Santa Clara, California, October 26, 2021 – Crocus Technology Inc., the leading supplier of disruptive Tunnel Magneto-Resistance XtremeSense® sensors, today announces the CT425, CT426, CT427 and CT428 isolated current sensors with <1% total error over the full operating temperature range without sacrificing accuracy or bandwidth.  The high-speed operation and accurate output allow customers to optimize system design for smaller sizes and higher efficiency.

The CT42x with less than 300 ns response time greatly simplifies the solution in EV Charging applications which are utilizing GaN (Gallium Nitride) or SiC (Silicon Carbide) transistors to improve power density.  Likewise, the CT42x offers improvements in performance and size compared to the classic isolated current sense solutions which utilize a shunt resistor, amplifier, and digital isolator to sense the voltage and convert this signal into a current measurement.  The CT42x directly senses the flow of current through the package avoiding errors in conversion and providing inherently faster and more accurate measurements.  With an industry-leading response time of 300 ns, high-power architectures like the CCM Totem-Pole PFC can provide higher power density solutions.  The fast switching frequency of Wide Bandgap (WBG) power devices requires a current sensor that can detect fast transients to prevent potential cascading failures.  The integration in a space-saving SOIC-8 package also reduces the total PCB footprint size by up to 8 times smaller compared to existing solutions.

The CT42x has robust built-in immunity to common-mode fields which allows the device to reject greater than 99% of external stray magnetic fields without the need for external shielding while maintaining <1% total accuracy.  Crocus’ proprietary TMR technology inherently offers a very high signal-to-noise ratio (SNR) which allows for high-resolution measurements required for precision control or monitoring applications.

“The expansion of this product family brings more options to our customers to experience the high precision performance of our XtremeSense TMR products in more demanding applications,”  states Zack Deiri, President and CEO of Crocus Technology.  “Previously our customers would select products that offered them a good performance on one parameter over temperature and then they would adjust their design to compensate for the other parameters.  With Crocus products they are finding they can achieve high precision and high bandwidth offering them a comprehensive high-performance solution.”

Product features and performance:

  • CT425 & CT428 (5.0 V version), CT426 & CT427 (3.3 V version)
  • Integrated 0.5 mW conductor enabling 20 A to 65 A AC and DC applications
  • Total output error ±0.5% FS (typ)
  • 300 ns response time, 1 MHz bandwidth
  • Rated Isolation Voltage: >4 kVRMS
  • AEC-Q100 & UL/IEC 62368 Certified, IEC 61000-4-5 Certified
  • Over current detection (CT427 & CT428), Enhanced filter (CT425 & CT426)
  • Integrated Common Mode Field Rejection (CMFR) with > 99% immunity

Targeting applications in Power-Factor Correction (PFC), Solar Power Inverters, Battery Management Systems (BMS), xEV Chargers, DC/DC converters and AC/DC inverters.

The CT425, CT426, CT427 and CT428 sensors are available in an industry-standard SOIC-8 package. Samples and evaluation boards are currently available.  For more information on the CT42x product family, please visit the product webpage:

About Crocus Technology

Crocus Technology develops and manufactures state-of-the-art magnetic sensors based on its patented XtremeSense® TMR sensor technology. Crocus’ disruptive magnetic sensor technology brings significant advancements to IoT and smart devices, industrial, consumer, medical, and automotive electronics applications demanding high accuracy, high resolution, stable temperature performance, and low power consumption. Crocus is headquartered in Santa Clara, California. For more information, please visit

© 2021 Crocus Technology International Corp.  All rights reserved.  Crocus Technology, XtremeSense® and combinations thereof are trademarks of Crocus Technology Inc. and Crocus Technology SA. Other names are for informational purposes only and may be trademarks of their respective owners.

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