POR

POWER

UP

SPINDLE

Z

(defaults)

CPR

BRAKE

START

NO SLEW

3ph EMF

CPR

limit

CPR

START

CCTR

No Slew

3ph EMF

limit

BRAKE

START*

SP_EN*

CPR*

SP_CLK

CPR=1's*

SP_CLK

POR

UV

SP_CLK*

SP_EN*

START*

REG BRAKE

RUN

SLEW

1ph EMF

CCTR

No limit

START*

SP_CLK

SP_EN

POR

REG BRAKE

UV

FAULT

TRISTATE

BRAKE

DELAY

THERMAL

TRISTATE

THSHUT

THWARN

UV

D97IN585

Figure 2: Spindle State Diagram.

NOTE: In the spindle state diagram, in transitioning from Start mode to Brake, the CPR register is shown

as being one possible path. The CPR register can be used to command a brake, which then causes the

outputs to brake. This is called CPR Brake mode. However, a true brake state does not really occur.

Specifically, current limit is still active.

NOTE: START and SP_EN bits and CPR is rewritten to get out of Spindle Z state. SP_EN must be

pulsed.

NOTE: All spindle state transitions require an SP_CLK edge.

VCM

GROUNDED

POWER

ON

VCM

ACTIVE

TRISTATE

REGISTER

PARK

VC_EN

REG PARK

DAC

(DONE=1)

SP_ENB

REG BRAKE

FAULT

BRAKE

DELAY

D97IN586

DELAY

VCM_TRISTATE

VC_EN

REG PARK

FAULT

PARK

FAULT

(FAULT)= POR or UV or TH_LIMIT

Figure 3: VCM section state diagram.

NOTE: VC_EN must be rewritten to get out of VCM Grounded state.

NOTE: At start, the spindle and VCM can now be simultaneously enabled. This is a VERY HIGH

POWER DISSIPATION mode. If this is done, be sure to use the SAT_SK bit and duty cycle the

VCM to keep chip power dissipation at a reasonable level.

L6256

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