Littelfuse Introduces LF21173TMR and LF21177TMR Omnipolar TMR Magnetic Switches for Battery-Powered Devices

Littelfuse,launched two new omnipolar magnetic switches, the LF21173TMR and LF21177TMR, which integrate Tunneling Magnetoresistance (TMR) and CMOS technologies in a compact LGA4 package. The devices operate over a voltage range of 1.8 V to 5.5 V and support multiple magnetic thresholds. They are designed for space-constrained, battery-powered applications including smart meters, electronic locks, medical devices, and portable consumer electronics.

Compared to conventional Hall-effect switches, the TMR-based switches offer higher magnetic sensitivity (9–30 Gauss) and lower power consumption. They feature fast response times and omnipolar operation, detecting both north and south magnetic poles without requiring specific magnet orientation.

Key features include:
Ultra-low power consumption to extend battery life
High magnetic sensitivity for reliable detection with smaller magnets
Wide operating voltage range (1.8 V–5.5 V)
Fast response for real-time sensing
Compact LGA4 package for miniaturized designs
Compatibility with standard CMOS circuits

TMR technology detects magnetic fields through changes in electrical resistance within magnetic tunnel junctions, producing stronger signal output at lower current levels compared to Hall-effect sensors that rely on Hall voltage. This results in reduced power use while maintaining ...