This application note introduces Atmel® ATA5795 as a building block to design a key fob with an integrated transponder and RKE functionality for the automotive industry.
Eigenschaften
Integrated key fob solution integrating MCU and a passive transponder functionality using Fc = 125kHz for immobilizer applications via a contactless LF interface and an RF transmitter functionality with programmable Fc = 300MHz to 433MHz for RKE applications
Transponder includes immobilizer SW stack supporting the immobilizer authentication protocol programmed at the factory
Open source immobilizer SW stack Is based on flexible communication protocol.
The protocol is configurable using transponder configuration memory
Immobilizer command set supports various classes of commands such as start authentication, read UID, read/write user memory, learn secret key1/2, and read transponder error status
Integrated high speed AES-128 hardware crypto module
Atmel ATA5795 includes segmented program and user data nonvolatile memories with protection locks
Ultra low power consumption enables passive transponder functionality at low coupling factors (k < 0.8% typ.)
Integrated RF transmitter module with selectable Fc using fractional PLL in ISM bands (315/430MHz)
Configurable radiated power output pout at up to +12.5dBm
Integrated flash-based Atmel ATmega 8-bit MCU includes ultra low-power design with many dedicated data communication and mixed-signal peripherals. Includes on-chip internal oscillators at 4MHz and 125kHz with RTC