DESCRIPTION
There are registers on chip to allow the setting of the desired spindle speed via the on chip Frequency Locked Loop (F.L.L.). No external components are required in the sensor-less operation as the control functions are integrated on chip (e.g. B.E.M.F. processing, digital masking, digital delay and sequencing). The V.C.M. drivers uses a transconductance amplifier, able to provide 2 different current ranges, suitable for seeking and tracking. When a low voltage is detected, a Power On Reset (P.O.R.) is issued and the internal registers are reset, the spindle power circuitry is tri-stated, B.E.M.F. synchronous rectification is enabled, the actuator retracts and then dynamic braking of the spindle is applied. These devices are built in BICMOS technology allowing dense digital circuitry to be combined with MOS\Bipolar power devices. 1/30 L6260 BLOCK DIAGRAM VREFOUT VREF/MINUS DAC/GND UV1 UV2 POR/DLY POR FCLK SDIO SCLK SLOAD R/W TEST TRISTATE ATEST DTEST BIAS - CIRCUIT 177 + PO...
STMicroelectronics
