US890_14 Datasheet, PDF (1/12 Pages) Melexis Microelectronic Systems – Two-Coil Fan Driver – High Output Current

US890 / US891
Two-Coil Fan Driver – High Output Current
Features and Benefits
0 Peak output current up to 1200mA
0 Low start-up voltage
0 Low output resistance
0 High sensitivity integrated Hall Sensor
0 Power-efficient CMOS and power MOSFETs
0 Built-in output protection clamping diode
0 Locked rotor protection and auto-restart
0 Integrated tachometer (US890) or alarm (US891)
signal protected output
0 Low cost
0 2-coil fan driver with FG/RD output in
RoHS Compliant 4-pin VK package
Application Examples
0 5V/12V DC brushless motor/fan
0 PC, server, laptop cooling fan
0 Power supply cooling fan
0 Large and small fan size
Ordering Code
Product Code Temperature Code
US891
E
US890
E
Package Code
VK
VK
Option Code
AAA-000
AAA-000
Legend:
Temperature Code:
Package Code:
Packing Form:
E for Temperature Range -40°C to 85°C
VK for Plastic Single in Line
BU for Bulk
Packing Form Code
BU
BU
Ordering example:
US891EVK-AAA-000-BU
1 Functional Diagram
2 General Description
The US890/891 is a one-chip solution for driving
two-coil brushless DC motors and fans.
Based on the advanced Melexis CMOS process,
the IC contains a Hall-effect sensor, dynamic
offset correction and powerful output drivers with
1200mA peak output current capability.
Specially designed for driving large fans, the
device is optimized for low start-up voltage.
Frequency Generator or Rotation Detection is
available. The open-drain output makes easier the
connectivity with any external interface such as
hardware monitoring or Super I/O IC.
These features are combined with the Melexis
patented no-V_DD design to fit the IC in a small 4-
pin VK package.
3901000890
Rev 003
Page 1 of 12
Data Sheet
Apr/12