LB11851MC Datasheet, PDF (1/5 Pages) ON Semiconductor – Microprocessor Fan Motor Interface Driver

Ordering number: ENA2091
LB11851MC
Monolithic Digital IC
Microprocessor Fan Motor
Interface Driver
http://onsemi.com
Overview
The LB11851MC provides an interface between a microcontroller motor control signal and external MOS transistors.
This device can implement a microprocessor fan driver with a minimal number of external components. The
LB11851MC is optimal for server and personal computer microprocessor fan drive in response to temperature or other
external signals when high precision and high air flow are required.
Features
• Fan motor interface driver function (FGIN)
⇒ This IC accepts a signal from a microcontroller and interfaces to external power transistors (PMOS and NMOS) to
provide high-efficiency low-power single-phase full-wave drive.
• Variable speed input pin (PWMIN)
⇒ PMOS side PWM control
NMOS side current regeneration using slow decay is used to achieve quite high-speed control.
• Built-in kickback absorption circuit (OUT1P/2P)
⇒ This circuit absorbs the kickback current that is generated at phase switching or power on/off to achieve smooth
current regeneration and protect the external transistors against destruction or degradation.
• Built-in current limiter circuit (SENSE)
⇒ This circuit implements a chopper-type current limiting control that operates at startup and during lock protection
mode.
The current detection voltage is set to a fixed 0.2V internally.
• Built-in microcontroller power supply (5VREG)
Semiconductor Components Industries, LLC, 2013
May, 2013
71112 SY 20120702-S00001 No.A2091-1/5