Expanded magnetic sensor portfolio with ultra-low-power omnipolar TMR switches

Littelfuse, Inc. has launched two next-generation omnipolar magnetic switches, the LF21173TMR and LF21177TMR. These devices combine TMR and CMOS technologies in a compact LGA4 package, providing ultra-low power consumption, exceptional magnetic sensitivity, and fast response for compact, battery-powered systems.

Designed for operation across a wide voltage range (1.8V–5.5V), the devices support multiple magnetic thresholds, allowing flexible integration into space-constrained applications such as smart meters, electronic locks, medical devices, and portable consumer electronics. Compared with conventional Hall-effect switches, these TMR devices deliver significantly higher sensitivity and lower power draw, helping engineers build smaller, more energy-efficient, and longer-lasting products.

“With the launch of the LF21173TMR and LF21177TMR switches, we’re bringing our customers a new level of precision and efficiency in magnetic sensing,” said Julius Venckus, global product manager, Sensors at Littelfuse. “By integrating advanced TMR technology, this switch delivers ultra-low power consumption and high sensitivity, solving key challenges in compact, battery-powered designs. It’s a game-changer for engineers building smarter, more reliable devices in industrial, medical, and consumer applications.”

Unlike conventional Hall-effect technology that relies on the Hall voltage generated by magnetic flux, TMR sensors measure resistance changes in magnetic tunnel junctions, producing stronger signal output at much lower current levels. The result is a switch that consumes less power while maintaining excellent accuracy and thermal stability, ideal for energy-constrained applications where every microamp counts.

Key Features and Benefits include:

• Ultra-low power consumption extends battery life in portable devices.
• High magnetic sensitivity (9-30 Gauss) ensures reliable detection with smaller magnets.
• Wide 1.8V–5.5V operating range supports flexible system integration.
• Fast response time enables precise, real-time sensing.
• Compact LGA4 package fits space-constrained designs.
• Omnipolar operation detects both the north and south poles, simplifying the layout.

Typical Markets and Applications include:

• Healthcare: Continuous glucose monitors and drug delivery pens, Building Automation Smart gas and water meters
• Consumer Electronics: Robotic appliances and portable devices
• Industrial Automation: Industrial controls and electronic locks
• Transportation: E-bikes, two-/three-wheelers, and off-highway vehicles

The LF21173TMR and LF21177TMR expand the company's magnetic sensors portfolio, empowering engineers to design the next generation of compact, energy-efficient smart devices that seamlessly sense, respond, and perform with precision.