Atmel Corp. has introduced a local interface network (LIN) system basis chip, ATA6620, with 6 kV ESD protection and low current consumption. Current consumption can be further reduced by a silent mode function that is not available in most other LIN2.0 devices. Manufactured in Atmel's 0.8 micron BCDMOS process technology, the ATA6620 is optimized for operation at up to 40 V, and in harsh environments, including door modules, seat control or intelligent sensors.
The ATA6620 includes a fully integrated LIN2.0 transceiver and a 5 V voltage regulator. The device interfaces the LIN protocol handler and the LIN bus. Improved slope control at the LIN bus is said to ensure secure data communication at up to 20 kilobaud with a resistive-capacitive oscillator for protocol handling. To meet 42 V power net requirements, the bus output can tolerate short circuits of up to 60 V. Normal, silent and sleep operating modes are available to ensure low current consumption, according to Torsten Mann, Atmel’s marketing director for automotive and control products. In silent mode the transmission path is disabled and the voltage regulator can supply a microcontroller in power-down mode. ATA6620 supply current is typically 40 microamperes in silent mode and 10 microamps in sleep mode.
Mann said its low current consumption suits the device for applications requiring cycling operation capability, such as scanning switches or flashing LEDs, with less than the usual average current consumption.
Protection features include overtemperature shutdown, short circuit protection, and high-voltage-bus-line protection up to 60 V. It is fully compatible with 5 V devices, and includes a dominant time-out function to prevent the bus line from being driven permanently in dominant state. A wake-up feature is implemented via the LIN bus line. The device also meets automotive qualification demands (protection against conducted interference, EMC and 6 kV ESD protection), and can withstand transients according to ISO/TR 7637/1.
