5v Hard Disk Drive Power Combo

The L6245 contains in a single chip all the func- tions to operate a sensorless brushless (DC) mo- tor and a voice coil motor, suitable for hard disk drive applications. The device is configured to Interface directly to an 8 bit parallel Microprocessor bus, and has a Register based architecture to reduce number of interconnection lines. All the positioning loop for sensorless spindle is integrated, including BEMF sensing, digital masking, digital delay and se- quencing. All Timing function are performed digi- tally, thus no external filtering components are re- quired. The VCM driver is a transconductance Amplifier able to provide 2 different current ranges, suitable for seeking or tracking of the head actuator. When a low voltage is detected, a monitor, in se- quence, resets the internal Registers puts in tris- tate the spindle powers, retracts the actuator, and applies the dynamic brake of the spindle. The L6245 is realized in Multipower-BCD 2 tech- nology, which combine isolate DMOS power tran- sistors with CMOS and Bipolar circuits in the same monolithic layer, and is assembled in a 64- pin PQFP. By STMicroelectronics