Passive entry

Passive Entry: The Passive Entry Device manages the Immobilizer communication, push button interaction and LF wake reception. The special high Q design achieves communication ranges up to 3m for the passive entry link without outstanding low standby current on the receiver side. The front-end offers flexible configuration of 2 different wake patterns of 74ACT16652DL 4, 8 or 16 bit length. Each channel could be adjusted in sensitivity and resonance frequency which results in reproducible system designs. By pressing a push button the device wakes up and controls an external UHF transmitter or transceiver. Security keys and rolling codes could be stored in the integrated EEPROM memory. This memory is accessible over the LF interface without support from the battery in the keyfob. The Passive Entry Device offers a special battery backup mode to operate the microcontroller without battery support. The external resonant circuit with a 74ACT16657DLR coil and a resonant capacitor could be trimmed to the correct resonant frequency with the integrated trimming capability achieving a easy way to eliminate part tolerances.