L6256 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

MFG CO.

L6256

12V COMBO

STMicroelectronics 

L6256

Figure 2: Spindle State Diagram.

POWER

UP

POR

CPR

BRAKE

CPR

UV

POR

SPINDLE

Z

(defaults)

START*

SP_EN*

CPR*

SP_CLK

START

NO SLEW

3ph EMF

CPR

limit

START

CCTR

No Slew

3ph EMF

limit

CPR=1's*

SP_CLK

START*

SP_CLK

RUN

SLEW

1ph EMF

CCTR

No limit

D97IN585

SP_CLK*

SP_EN*

START*

REG BRAKE

BRAKE

BRAKE

DELAY

SP_EN

POR

REG BRAKE

UV

FAULT

TRISTATE

THSHUT

THWARN

UV

THERMAL

TRISTATE

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.

Figure 3: VCM section state diagram.

POWER

ON

VCM_TRISTATE

TRISTATE

VCM

VC_EN

GROUNDED

DAC

DELAY

VC_EN

(FAULT)= POR or UV or TH_LIMIT

REG PARK

REG PARK

REGISTER

PARK

VCM

ACTIVE

SP_ENB

FAULT

REG BRAKE

FAULT

FAULT

PARK

(DONE=1)

BRAKE

DELAY

D97IN586

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.

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