Atmel’s Ultra-low Power MCU Targets Car Key Fobs
Don’t you hate it when you press on the key fob for your car and nothing happens. With me, I admit, it’s usually the press that’s the problem rather than the battery in the fob. But I do worry about it. Apparently, Atmel sees this as one of the problems of car key fobs, too. The company’s latest MCU attempts to solve this problem by offering ultra-low power technology to extend the battery life of a car key fob.
Atmel’s new ultra-low power AVR microcontroller, the ATA5790N, announced today along with the AES-128 immobilizer protocol stack, takes aim at not only at power consumption but also at security issues. The MCU includes LF immobilizer functionality and a 3D LF receiver in a single 5mm x 7mm package. When combined with the companion device ATA5830 RF transmitter, the IC takes dead aim at high-volume uni- and bi-directional car key fobs for passive entry and passive start systems.
A built-in AES-128 cryptographic engine, along with the Atmel protocol stack, is expected to provide maximum security protection with fast authentication time, which is critical to immobilizer systems. As an open-source solution, AES-128 encryption is far more secure, Atmel says, than competitive proprietary solutions since peer reviewing increases fault detection.
So how much current does this MCU consume? Not much. Listening mode consumption is less than 4.5 microampere. Lower current consumption, of course, can extend the battery life significantly for car key fobs.
Other features of the MCU are 16k Flash and 2k EEPROM. Within the 16k Flash, 14kB is available for the application software, while 2kB is available for the immobilizer functionality. The core is surrounded by specific hardware accelerators, which allows designers to implement any immobilizer protocol in the software without the typical current consumption impact. Samples of the ATA5790N are now available in 5mm x 7mm QFN38 packages. Pricing starts at $1.80 USD for 10,000-piece quantities.
To simplify and accelerate product development, the device hosts the application code in Flash and is supported by the standard AVR development tool chain (automotive-grade C compiler and AVR Studio® IDE). Additionally, a remote keyless entry development kit (ATAPMxxxx) with several daughter boards provides complete reference designs for both hardware and software.
