BA6901F

Motor driver ICs

5/10

!

Circuit operation

•Lock detect circuit, automatic restart circuit

Charge and discharge time at motor lock condition varies with the value of external capacitor at LD terminal, and is

given by the following equation.

Ton (Charge time)

=

ILDC

C

× (VLDCL−VLDCP)

Toff (Discharge time)

=

ILDD

C

× (VLDCL−VLDCP)

C

VLDCL

VLDCP

ILDC

ILDD

Value of capacitor at LD terminal

Clamp voltage of capacitor

Comparison voltage of capacitor

Charge current of capacitor

Discharge current of capacitor

:

:

:

:

:

(2.40V

Typ.)

(0.60V

Typ.)

(5.0

µA

Typ.)

(0.5

µA

Typ.)

The following value shows charge time and discharge time at C

=1.0µF for reference.

Charge time

=0.36sec.

(Output : ON)

Discharge time

=3.60sec.

(Output : OFF)

Shows timing chart of LD terminal.

Toff

Output Tr. OFF

VLDCL

Motor lock

Detect lock

Lock cancel

Depend on the hall output

Reset ordinary motion

H

+

A1

LD

AL

ALB

HO

VLDCP

ON

Ton

HIGH(Open collector)

LOW