Transponder coils have extremely small dimensions

March 18, 2015 // By Christoph Hammerschmidt
Applications such as tire pressure monitoring systems (TPMS) require components with extremely compact dimensions. For this kind of use cases, TDK Corp. has designed a range of SMT transponder coils that will me marketed under the company's Epcos brand.

Measuring just 4.5 mm x 3.2 mm x 3.2 mm, the TC1812 has an inductance of 2.38 mH and is designed for operation in the Z-axis. The TC1210 coil is available with an inductance value of 1.08 mH or 1.34 mH, depending on type, and is suitable for operation in either the X- or Y-axis. Furthermore, both TC1210 versions are currently the smallest transponder coils in the world as they measure just 3.2 mm x 2.5 mm x 2.2 mm.

Thanks to the reduced dimensions, it has also been possible to reduce the mass of the components by about a third compared to the predecessor products. For example, the TC1210 (B82450A1084C000) weighs just 50 mg, while the TC1812 (B82451A2384D000) weighs only 120 mg. This makes them an excellent choice for tire pressure monitoring systems (TPMS). These applications demand especially robust, low-mass components due to the high acceleration forces that are encountered. The terminals of the windings are laser-welded and provide high mechanical stability.

The TC1210 coil has a high sensitivity of 3.1 mV/µT or 3.5 mV/µT, depending on the type, while the TC1812 coils offers a sensitivity of 7.6 mV/µT. All new transponder coils are designed for a center frequency of 125 kHz, comply with the AEC-Q200 standard and are RoHS-compatible.

More information: TDK