Diodes AH5798 - Manual (Page 2)

AH5798
SINGLE PHASE HALL EFFECT LATCH SMART
FAN MOTOR CONTROLLER
AH5798
Document number: DS32001 Rev. 2 - 2
2 of 11
www.diodes.com
June 2010
© Diodes Incorporated
Typical Application Circuit
V
dd
FG
O1
O2
FG
SYSTEM
POWER
V
SS
SYSTEM
POWER
10Kohm
AH5798
Dz C1
D1
* Reverse connection of power supply may damage the device. To prevent reverse power damage, a protection (reverse blocking)
Diode D1 is needed between power supply and Vdd terminal. If a reverse power protection diode D1 is used, there
is no current return path to power supply, so it is necessary to follow measures such as below.
- Connect Dz (Zener diode) between Vdd and Vss terminal, to prevent voltage exceeding the absolute maximum rating of the device.
- Connect a capacitor C1 between Vdd and Vss terminal, to complete the current return path to power supply.
The AH5798 has an open-drain tachometer FG output that follows the magnetic change frequency. Typically, a pull-up resistor of 10k
Ω is
recommended from FG pin to the supply voltage.
Pin Descriptions
Pin Name Description
Vdd Power Supply Pin
Vss Ground Pin
O1 Output Driving & Sinking Pin 1
O2 Output Driving & Sinking Pin 2
NC No Connection
FG Frequency Generator (Note 1)
Notes: 1. The FG is the same as the magnetic change frequency.