At Convergence 2008, Atmel introduced ATA6833 and ATA6834 driver ICs for brushless DC motor applications such as fuel pumps, turbo chargers, or exhaust gas recirculation, which demand high reliability, and for premium-class convenience electronics such as power window or seat adjustment applications, which benefit from the drivers’ low noise characteristics.
Both devices are manufactured using Atmel’s high-voltage 0.8 um BCD-on-SOI technology, which enables the use of 7 mm x 7 mm QFN packages. The ATA6833/34 include integrated driver, watchdog, voltage regulator, and LIN interface functionality in a single IC. The firm noted that the high integration level facilitates extremely small designs, helps to reduce overall system costs by about a third, and improves board quality by reducing the number of solder joints.
The ATA6833 is a BLDC motor System Basis Chip with 3 half-bridge gate drivers. The 3 push-pull stages with integrated charge pump can drive 6 external NMOS transistors. The integrated watchdog monitors a microcontroller, such as Atmel's automotive-qualified ATmega32M1, which is supplied by an integrated voltage regulator programmed to 5 V or 3.3 V output voltage, thus providing 100 mA current capability. An integrated LIN 2.1 transceiver based on Atmel's stand-alone ATA6662 completes the system basis features. Current consumption in standby mode is less than 50 microampere.
The ATA6834, the ATA6833's high-temperature companion, handles operating chip temperatures of up to 200°C and is suited for under-the-hood applications in which actuators handle the flow of hot exhaust gas or hot oil. The ECUs can be attached to a turbo charger or used to build a mechatronic unit along with a pump motor. The ATA6833/34 provide protection features including a two-stage thermal warning and thermal shut-off as well as open-load, overload, short-circuit, and undervoltage detection with switch-off functionality. Built-in shoot-through protection helps to avoid dangerous simultaneous activation of a high-side and a low-side transistor between supply and ground. Customers can adapt the dead time to the needs of their NMOS transistors by the value of an external resistor/capacitor combination.
The devices meet automotive qualification demands (protection against conducted interference, EMC, and ESD protection) and can withstand transients as specified in ISO/TR 7637. Samples are available now. Pricing starts at $2.95 for the ATA6833 and $3.30 for the ATA6834 for 10k-piece quantities each. An application board for development support, including a programmed AVR microcontroller, is available for $139.