Atmel Corporation has combined an 8-bit AVR flash microcontroller with an RF transmitter in two new devices that target tire pressure monitoring systems.
The ATA6285 and ATA6286 are designed to control and transmit data gained from capacitive pressure and motion sensors, and are said to include all of the building blocks needed for measurement and calibration of simple capacitive pressure and motion sensors plus complete RF transmission functionality.
The devices allow system designers to select low-cost, non-calibrated sensors that can subsequently be calibrated by firmware within the microcontroller. They feature an integrated temperature sensor with shut-down mode, a 90 kHz slow-oscillation mode for timer wake-up in sleep mode, and an LF input with several header options. Current consumption ranges from 0.5 µA to 0.85 µA in sleep mode, and is as low as 200 µA during sensor measurement, or about 10 times less than in piezo-resistive sensor solutions. Current consumption in transmission mode is typically 8.5 mA at 6 dBm, and the integrated 125 kHz programmable wake-up receiver channel consumes less then 1.7 µA in active listening mode.
The ATA6285 operates at 315 MHz and the ATA6286 at 433 MHz. Both devices are suited for ASK and FSK transmission with a typical data rate of 10 kBaud in Manchester mode. The parts can be operated at 2 V to 3.6 V from a single Li-Ion cell power supply at operating temperatures from -40 °C to 125 °C and storage temperatures of -40 °C to 150 °C.