New Omnipolar TMR magnetic switches from Littelfuse

The new devices, LF21173TMR and LF21177TMR, integrate Tunneling Magnetoresistance (TMR) technology with CMOS architecture in a small LGA4 package. According to the company, this combination delivers ultra-low power consumption, high magnetic sensitivity, and rapid response times – features that make them well-suited for battery-powered systems.

Operating across a voltage range of 1.8 V to 5.5 V, the switches support multiple magnetic thresholds, enabling flexible design options for space-constrained products such as smart meters, electronic locks, medical equipment, and portable consumer electronics. Littelfuse says the TMR-based design offers significantly greater sensitivity and lower energy draw compared to conventional Hall-effect switches, helping engineers develop smaller, longer-lasting devices.

“By integrating advanced TMR technology, this switch delivers ultra-low power consumption and high sensitivity – solving key challenges in compact, battery-powered designs,” the company stated.

Unlike Hall-effect sensors, which detect magnetic flux through Hall voltage, TMR sensors measure resistance changes in magnetic tunnel junctions. This approach produces stronger signal output at lower current levels, resulting in improved accuracy and thermal stability while minimising power usage – an advantage for applications where energy efficiency is critical.