US91AEVK-AAA-000-BU

US90A/US91A Datasheet 1. Features and Benefits 3. Description Integrated High sensitivity Hall Sensor The US90A/91A is a one-chip solution for driving two-coil brushless DC cooling fans. No VDD concept Locked rotor protection and auto-restart Based on the advanced Melexis CMOS process, the IC contains a Hall-effect sensor, dynamic Power-efficient CMOS and power MOSFETs offset correction and low side output drivers. Built-in output protection clamping diode Frequency Generator or Rotation Detection is Integrated tachometer (FG: US90A) or alarm available. The open-drain output makes the (RD: US91A) signal output connectivity with any external interface such as FG/RD SIP package options: hardware monitoring or Super I/O IC easier. 4 pins VA and VK package These features are combined with the Melexis SMD package options patented no-VDD design to fit the IC in small 4-pin VK and VA package. The device is also delivered in SOIC8 bent leads DC package for automatic assembly. SOT25 straight leads RoHS Compliant Peak current up to 500mA 2. Application Examples 12V and 24V 2-coil fans Figure 1 REVISION 06 20 JUL 2017 US90A/US91A Datasheet Contents 1. Features and Benefits ............................................................................................................................ 1 2. Application Examples ............................................................................................................................. 1 3. Description ............................................................................................................................................ 1 4. Ordering Information ............................................................................................................................ 3 5. Glossary of Terms .................................................................................................................................. 4 6. Pin Definitions and Descriptions ............................................................................................................ 4 7. Electrical Specifications ......................................................................................................................... 5 7.1. Absolute Maximum Ratings ............................................................................................................... 5 7.2. General Electrical Specifications ........................................................................................................ 5 7.3. Magnetic Specifications ...................................................................................................................... 6 7.4. Driver output vs Magnetic pole ......................................................................................................... 6 8. Description ............................................................................................................................................ 7 8.1. General description ............................................................................................................................ 7 8.2. No-VDD concept ................................................................................................................................. 7 8.3. LRP ....................................................................................................................................................... 7 9. Performance Graphs.............................................................................................................................. 8 10. Application Information ....................................................................................................................... 9 11. Package Information .......................................................................................................................... 10 11.1. VK Package Information (4-pin TO92) ........................................................................................... 10 11.2. Trimmed VK T&R(dead bug) : VKAAA000-RX ............................................................................... 10 11.2.1. VKAA000-RX Tape ..................................................................................................................... 11 11.2.2. VKAAA000-RX Lead Trim length ............................................................................................... 11 11.3. DC Package Information (8-pin narrow SOIC) ............................................................................... 11 11.4. VA Package Information (4-pin TO92 flat) ..................................................................................... 12 11.5. ZE Package (SOT25 with straight leads) ......................................................................................... 14 12. Standard Information ........................................................................................................................ 14 13. ESD Precautions ................................................................................................................................. 15 14. Disclaimer .......................................................................................................................................... 15 15. Revision History Table ....................................................................................................................... 16 16. Contact .............................................................................................................................................. 16 REVISION 006 20 JUL 2017 Page 2 of 16