EMC2112 Datasheet, PDF (1/65 Pages) SMSC Corporation – RPM-Based Linear Fan Controller with Hardware Thermal Shutdown

EMC2112
RPM-Based Linear Fan
Controller with Hardware
Thermal Shutdown
PRODUCT FEATURES
Datasheet
General Description
The EMC2112 is an SMBus, closed-loop, RPM-based
fan driver with hardware (HW) thermal shutdown and
reset controller. The EMC2112 offers a single High Side
fan driver capable of sourcing up to 600mA from a 5V
supply.
The EMC2112 utilizes Beta Compensation (an
implementation of the BJT or transistor model for
thermal diodes) and Resistance Error Correction (REC)
to accurately monitor up to three (3) external
temperature zones. These features allow great accuracy
for CPU substrate thermal diodes on multiple process
geometries as well as with discrete diode-connected
transistors. Both Beta Compensation and REC can be
disabled on the EMC2112 to maintain accuracy when
monitoring AMD thermal diodes.
The EMC2112 provides a stand-alone HW thermal
shutdown block. The HW thermal shutdown logic can be
configured for a few common configurations based on
the strapping level of the SHDN_SEL pin on the PCB.
The HW thermal shutdown point can be set in 1°C
increments by using a discrete resistor connected to the
TRIP_SET pin.
The EMC2112 also provides 5V supply ‘power good’
function with a threshold of 4.5V. This function is
provided on the RESET pin.
Applications
„ Notebook Computers
„ Desktop Computers
„ Embedded Applications
Features
„ Closed-Loop RPM-Based Fan Controller
— 1% accuracy with external clock input
— 3% accuracy with internal clock
— Internal clock can be used as a source
— Aging fan detection
„ Integrated Linear Fan Driver
— 600mA drive capability
„ HW Thermal Shutdown (SYS_SHDN)
— 1°C incremental set points for thermal shutdown
— Cannot be disabled by software
„ Provides Reset Function (RESET) On 5V Supply
„ Up to Three (3) Remote Thermal Zones
— ±1°C accuracy (60°C to 100°C)
— 0.125°C resolution
— Designed to support 45nm, 65nm, and 90nm CPU
Diodes using BJT and transistor model
— Eliminates temperature offset due to series resistance
from PCB traces and thermal ‘Diode’
„ Operates From Single 3.0 - 3.6V Supply
— 5V supply for linear fan driver and reset generator
„ SMBus 2.0 and I²C compatible
— User selectable SMBus address using pull-up resistor
on ADDR_SEL pin
— Supports Block Read and Write functionality
„ Available in 20-pin, 4x4 QFN Lead-free RoHS
Compliant package
SMSC EMC2112
DATASHEET
Revision 0.88 (11-20-09)