AH5798

SINGLE PHASE HALL EFFECT LATCH SMART

FAN MOTOR CONTROLLER

AH5798

Document number: DS32001 Rev. 2 - 2

3 of 11

www.diodes.com

June 2010

© Diodes Incorporated

Functional Block Diagram

Frequency

Generator

Lock detect,

Shoutdown and

Automatic re-start

Soft Switching

Control

Hall

Sensor

AMP

Vdd

FG

O1

O2

Power

Vss

Control

Logic

Full Bridge

Driver

Operating

FG

O1

O2

Ton

Toff

“Re-start spinning”

motor locked cleared

motor locked detected

Mechanical lock

Magentic

S

N

Normal spinning

Notes:

2. In “Normal spinning”, the FG changes its state at each rising edge of O1.

3. 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.

4. 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.