US79 Series

CMOS Power Hall IC

39010US79

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DataSheet

Rev. 006

Feb/04

Features and Benefits

• Built-in RFI Filter

• Power Efficient CMOS and Power MOSFET Drivers allow 400mA without

overheating

Applications

• Fan sizes up to 90mm

• Current range up to 400mA

Ordering Information

Part No.

Temperature Suffix

Package Code

US79

K (-40°C to 125°C)

UA (TO-92 flat)

1. Functional Diagram

2. Description

The US79KUA is the most advanced Smart Fan

Control Hall IC. It is designed for 5V and 12V

cooling commutation. The chip contains many

features

to

allow

survival

in

a

harsh

environment. The IC was designed to eliminate

all discrete components such as capacitors,

resistors, transistors, diodes, PC board and

associated labor, replacing US$0.25 to US$0.35

in direct cost.

The K rating guarantees proper operation up to

an ambient temperature of 125°C. Hall IC

circuitry and power FET output provide a low

power dissipation cool chip.

Locked Rotor conditions are detected by the IC

when there is no motion for one second and will

shut off the motor drive for five seconds. Then,

the IC will turn on the drive current for one

second. This sequence continues indefinitely

until the locked rotor condition is fixed. This

feature prevents overheating.

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