AH287Z4-AE1 BCDSEMI [BCD Semiconductor Manufacturing Limited], AH287Z4-AE1 Datasheet - Page 10

• Manufacturer Part Number: AH287Z4-AE1
• Description: TWO PHASE HALL EFFECT LATCH WITH LOCKED PROTECTION
• Manufacturer: BCDSEMI [BCD Semiconductor Manufacturing Limited]

Operating Diagram (Note 3)
Note 3: The automatic restart circuit detects a motor lock condition and automatically turns off the output current.
When the lock is cleared, the IC automatically restarts and allows the motor to run. In AH287, automatic restart
is performed in the following manner. A motor lock condition is detected when the Hall signal stops switching.
The output is ON when CT pin is being charged, and OFF when CT pin is being discharged.
Output ON time (T
capacitor.
V
V
I
I
Aug. 2008 Rev. 1. 1
T
T
CHG
DHG
Motor Output
TWO PHASE HALL EFFECT LATCH WITH LOCKED PROTECTION
OFF
CL
CP
ON
is the CT pin clamp voltage
is the CT pin comparator voltage
=
Hall Input
is the CT pin charge current
=
is the CT pin discharge current
C
C
( *
( *
V
V
I
CT
I
CL
CHG
CL
DHG
−
−
V
V
CP
CP
)
)
ON
(
(
Sec
Sec
) and OFF time (T
)
)
Motor locked
Motor lock detected
Figure 13. Control Timing Diagram of AH287
OFF
) are determined by C, the capacitance of the CT pin external
OFF
CT
Clamp
Voltage
10
T
ON
ON
CT
Comparator
Voltage
T
OFF
BCD Semiconductor Manufacturing Limited
Reverts to normal operation
Motor lock
cleared
Data Sheet
AH287