US79 Series CMOS Power Hall IC 1. Features and Benefits 2. Applications Built-in Reverse Voltage Protection Fan sizes up to 90mm Current range up to 400mA 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 3. Ordering information Product Code Temperature Code Package Code Option Code Packing Form Code US79 K (-40C to 125C) UA (TO-92 flat) AAA-000 BU 4. Functional Diagram 5. 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 125C. 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. REVISION 010 - SEP 15, 2021 Page 1 of 10 39010US79 US79 Series CMOS Power Hall IC Contents 1. Features and Benefits ........................................................................................................................................ 1 2. Applications ................................................................................................................................................................1 3. Ordering information ......................................................................................................................................... 1 4. Functional Diagram ............................................................................................................................................ 1 5. Description..................................................................................................................................................................1 6. Glossary of Terms .............................................................................................................................................. 3 7. Absolute Maximum Ratings ............................................................................................................................... 3 8. US79 Electrical Specifications ........................................................................................................................... 3 9. US79 Magnetic Specifications ........................................................................................................................... 4 10. Unique Features............................................................................................................................................... 4 11. Performance Graphs ....................................................................................................................................... 5 12. Applications Information ................................................................................................................................. 6 13. Standard information regarding manufacturability of Melexis products with different soldering processes ...................................................................................................................................................................7 14. ESD Precautions ............................................................................................................................................... 7 15. UA Package Information .................................................................................................................................. 8 15.1. Hall plate location ............................................................................................................................. 8 15.2. AAA000 Package variant .................................................................................................................. 8 16. Revision history .............................................................................................................................................. 10 17. Contact................................................................................................................................................................... 10 18. Disclaimer .............................................................................................................................................................. 10 REVISION 010 - SEP 15, 2021 Page 2 of 10 39010US79