The ATA5790 is a highly integrated low-power AVR® microcontroller including LF functionally for Passive Entry and Passive Start car keys, where both immobilization and Passive Entry/ Passive Start functions need to be in one single key. Housed in a single 5mm x 7mm QFN38 package, the IC is partitioned into three sections: LF 3D front end, LF 1D transponder front end, and low-power 8-bit AVR® microcontroller. The ATA5790 offers very low current consumption, in listening mode it is about 5 microampere. The 3D LF receiver with RSSI operates at 2.5mVpp worst case. The built-in AES-128 cryptographic engine, along with the Atmel® protocol stack, provides maximum security protection with fast authentication time. The AES-128 cryptography engine is accessible by both the immobilizer and the PEPS unit. The immobilizer interface can run in contactless mode, allowing energy supply and data transmission via the LF link.