General Description
The US90A/91A is a one-chip solution for driving two-coil brushless DC cooling fans.
Based  on  the  advanced  Melexis  CMOS  process, the  IC  contains  a  Hall-effect  sensor,  dynamic offset correction and low side output drivers.

FEATUREs and Benefits
 Low cost
 High sensitivity Hall Sensor
 Locked rotor protection and auto-restart
 Power-efficient CMOS and power MOSFETs
 Built-in output protection clamping diode
 Integrated tachometer (US90A) or alarm (US91A) signal output
 2-coil fan driver with FG/RD output in 4-pin VK / VA and 8-pin narrow SOIC packages (all RoHS Compliant)

APPLICATION Examples
 12V/24V fans
 Peak current up to 500mA