Magnetic-sensing with Accuracy Linearity Dynamic Range and Sensitivity

Texas Instruments (TI) today introduced the industry's first magnetic sensing IC with a fully-integrated fluxgate sensor and compensation coil driver, along with all the required signal conditioning circuitry. Complete integration enables the DRV421 to provide best-in-class sensor accuracy and linearity, high dynamic range, and simpler system design compared to traditional Hall-effect-based closed-loop sensors. With the DRV421, system designers will be able to more easily develop magnetic closed-loop current sensors for applications such as motor control, renewable energy, battery chargers and power monitoring.

Key benefits of the DRV421 IC include: Simplifies system design: An integrated fluxgate sensor reduces the design footprint, simplifies assembly and reduces the complexity of an external fluxgate sensor design. Sensor integration enables best-in-class accuracy and linearity: Allows precise control over motors and automation equipment with an overall sensor accuracy of less than 0.1 percent. Reduces coupling between the compensation coil and the fluxgate sensor, as well as emissions from fluxgate excitation, to provide high linearity. High dynamic range: Built-in closed-loop magnetic core degaussing procedure and offset calibration increase dynamic range up to six decades while supporting higher system-level accuracy, compared to traditional solutions. Allows 3.3-V operation: As the first fluxgate sensor solution on the market supporting 3.3-V operation, the DRV421 simplifies the interface to integrated ADCs on low-power microcontrollers.

The DRV421 evaluation module (DRV421EVM) enables designers to quickly and easily evaluate the new current sensing IC’s features and performance. It is available for purchase for US$49 via the TI store and authorized distributors. In addition, Sumida Corp. has introduced the SC2912, a magnetic module that system designers can place on top of the DRV421 as a printed circuit board (PCB) component. This allows engineers to design universal platform solutions targeting a wide range of current levels while choosing the appropriate magnetic module for their specific use case.

“The novel and intuitive approach of our DRV421 complementary module gives customers a new degree of freedom for a closed-loop sensor module,” said Mr. Seiji Shimizu, assistant manager of signal and power solutions for the Automotive and Industry Business Unit, Sumida. “The combination of our module technology and TI’s DRV421 gives customers an unprecedented level of accuracy, linearity, dynamic range, sensitivity and ease of use.”

The DRV421 comes in a 4-mm-by-4-mm quad flat no-lead (QFN) package. Pre-production samples are available now. Production quantities will be available in 3Q2015 for a price of US$2.50 in 1,000-unit quantities.