Feature-packed BLDC motor ICs trim overall system cost

Atmel Corp. has released ATA6833 and ATA6834 highly integrated driver ICs for brushless DC (BLDC) motor applications such as fuel pumps, turbo chargers, or exhaust gas recirculation. The new devices can also be used for premium-class convenience electronics such as power window or seat adjustment applications, which benefit from the low noise of the new BLDC motor driver ICs. Both devices are manufactured using Atmel's high-voltage 0.8?m BCD-on-SOI technology, which enables the use of much smaller lower-cost 7mm x 7mm QFN packages.

The ATA6833/34 claimed to be the first BLDC motor driver ICs with integrated driver, watchdog, voltage regulator and LIN interface functionality in a single IC. This facilitates extremely small designs and helps to reduce overall system costs by about a third. Furthermore, the high integration level improves board quality by reducing the number of solder joints.

The ATA6833 is a BLDC motor system basis chip with three half-bridge gate drivers. The three push-pull stages with integrated charge pump can drive six external NMOS transistors. The integrated watchdog monitors the MCU, which in turn is supplied by an integrated voltage regulator programmed to 5- or 3.3V output voltage providing 100mA current capability. An integrated LIN 2.1 transceiver—based on Atmel's stand-alone LIN transceiver ATA6662—completes the system basis features. In standby mode, the current consumption is less than 50?A.

The ATA6834, the ATA6833's high-temperature companion, handles operating chip temperatures of up to 200?'C and is suitable for all high-temperature "under-the-hood" applications where actuators handle the flow of hot exhaust gas or hot oil. To implement space-saving designs, 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 several 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. To protect the external NMOS transistors, a 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.

These devices meet the strict automotive qualification demands (protection against conducted interference, EMC and ESD protection) and can withstand transients as specified in ISO/TR 7637.

Samples of the new brushless motor driver ICs ATA6833/34 are available in QFN48 packages measuring only 7mm x 7mm. Pricing starts at $2.95 for the ATA6833 and at $3.30 for the ATA6834 for 10,000-unit quantities each. An application board for development support, including a programmed AVR MCU, can be ordered for $139.