US79_14 Datasheet, PDF (1/9 Pages) Melexis Microelectronic Systems – CMOS Power Hall IC

US79 Series
CMOS Power Hall IC
Features and Benefits
Built-in Reverse Voltage Protection
Built-in RFI Filter
Power Efficient CMOS and Power MOSFET Drivers allow 400mA
without overheating
Built-in Zener Diodes Protect
Outputs Eliminate all Fan
Components Eliminate PC
Board
5V and 12V Operation
High Sensitivity for switching symmetry
Locked Rotor Shutdown
Applications
Fan sizes up to 90mm
Current range up to 400mA
Ordering Code
Product Code Temperature Code
US79
K
Package Code
UA
Option Code
AAA-000
Legend:
Temperature Code:
K for Temperature Range -40°C to 125°C
Package Code:
UA for TO-92(flat)
Option Code:
xxx-000: Standard version
Packing Form:
BU for Bulk
Packing Form Code
BU
Ordering example:
US79KUA-AAA-000-BU
1. Functional Diagram
39010US79
Rev. 007
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.
Page 1 of 9
DataSheet
Apr/12