AN1139 STMicroelectronics, AN1139 Datasheet - Page 10

• Manufacturer Part Number: AN1139
• Description: L6254 - L6268 - L6269 12V DISK DRIVE POWER COMBO IC
• Manufacturer: STMicroelectronics

AN1139 APPLICATION NOTE
Reg#4: Bit0~Bit7, Spindle FLL coarse counter C4...C11
Reg#5: Bit0~Bit2, Spindle FLL fine counter F8...F10
Reg#6: Bit0~Bit7, Spindle FLL fine counter F0...F7
Reg#7: Read Only Register
Reg#8: Bit0, Spindle PWM (chopping) slew rate,“1” 20V/ S, “0” 10V/ S
Reg#9: Bit0~Bit1, VCM retract voltage
Reg#10: Bit4, “1” Spindle Mechanical or Electrical output, “0” Spindle Zero cross output
Reg#11: Bit0, VCM PSM (chopping) Slew Rate,“1” 20V/ S, “0” 10V/ S
Reg#12: Read Only Register
3.3
The Status register (Reg#7) and the Identification register (Reg#12) are READ only registers, while all the oth-
ers are only WRITE registers. The Status register provides informations of the Spindle motor (Bits 2...7) and
the Thermal behaviour of the device (Bits 1,2).
10/64
THERMAL - Bit #0. Normally is set to 1, when the Junction temperature reaches about 160 C, the bit
will be set to 0. This will automatically tristate the Spindle outputs and the Voice Coil will initiate the
STATUS AND IDENTIFICATION REGISTERS
Bit4~Bit5, Spindle start-up current limitation
Bit1~Bit2, Spindle PWM mode Minimum ON time
Bit3, “1” 8 pole Spindle motor, “0” 12 pole Spindle motor
Bit4~Bit7, Spindle Commutation Delay control SD0....SD3
Bit3, “1” Spindle Two phase brake ((*)only L6254), “0” Spindle Three phase brake
Bit4~Bit7, Spindle FLL coarse counter C0...C3
Bit0, “0” Thermal Shutdown ( >= 160 C)
Bit1, “0” Thermal Warning ( >= 125 C)
Bit2, “0” Spindle Bemf not detected
Bit3, “1” Rapid deceleration of the Spindle motor or High frequency on FCOM signal.
Bit4, Spindle Mask time signal, “0” Spindle bemf is masked
Bit5, “0” Spindle speed lock error (>16 S/sample)
Bit6, “0” Spindle is in the Internal Start-Up ALIGN Phase
Bit7, “0” Spindle is in the Internal Start-Up GO Phase
Bit1, Charge pump current in Spindle FLL loop, “1” 25 A, “0” 100 A
Bit3, “1” Presets Spindle inductive sense start-up circuits
Bit6, “1” Forces Spindle FLL charge pump low
Bit7, “1” Forces Spindle FLL charge pump high
Bit2, “1” Connects the voltage reference (2V) for VCM calibration
Bit3~Bit6, VCM retract time
Bit4, “1” Doubles the times for the internal Spindle Align and Go Start-Up
Bit5, “1” Enables VCM
Bit7, “1” Initiates the VCM retract
Bit5, “1” Spindle reverse brake
Bit7, “1” Disables Vboost
Bit1, “1” Forces VCM outputs to be high in PSM mode
Bit2, “1” Unused (Future Power saving mode)
Bit3, “1” Spindle PWM (phase commutation) slew rate “1” 2V/ S, “0” 30V/ S
Bit0~Bit7, for chip ID