Diodes AH5795 - Manual (Page 6)

AH5795
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
AH5795
Document number: DS35277 Rev. 1 - 2
6 of 13
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August 2011
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T
Operating Characteristics (cont. Note 7, 8, 9 and 10)
FG
O1
O2
Ton Toff
“Re-start spinning”
motor locked cleared motor locked detected
Mechanical lock
Magentic
S
N
Normal spinning
Truth Table
O1 O2 PWM FG
L H H L
H L H H
L L L X (Note 10)
Notes: 7. In “Normal spinning, the FG changes its state at each edge of O1.
8. When the motor locks with South pole at the Hall element, O2 is kept on “L” and O1 is a clock with Ton/Toff ratio. When motor locks with North pole
at the Hall element, O1 is kept on “L”, O2 is a clock with Ton/Toff ratio.
9. When “Re-start spinning” occurs, the motor speed ramps up to the “Normal Spinning” speed from zero. Speed ramp-up profile depends on motor
characteristics.
10. X: H or L depends on magnetic pole north or South