Passive Low Frequency Interface Device (PaLFI) With EEPROM and 134.2 kHz Transponder Interface

The TMS37157 combines a Low Frequency Transponder Interface with an SPI Interface and Power Management for a connected microcontroller. It is the ideal device for any Configuration, Data Logger-, Sensoror Remote Control Application. The Transponder memory is accessible through SPI and LF and, in the second case, operates without the need for a battery. The use of the Low Frequency Band ensures a communication in a defined direction and harsh environments.

The TMS37157 manages the Transponder communication and push button interaction. During sleep state the devices enters a special low power mode with only 60 nA current consumption.

The EEPROM memory is accessible over the LF interface without support from the battery or through SPI by a microcontroller if a battery is connected. The TMS37157 offers a special battery charge mode.

The external resonance circuit with a LF coil and a resonance capacitor can be trimmed to the correct resonance frequency with the integrated trimming capability achieving an easy way to eliminate part tolerances.

The small RSA 16-pin package together with only a few external components results in a cost efficient design.