EMC2104
Dual RPM-Based PWM Fan
Controller with Hardware
Thermal Shutdown
PRODUCT FEATURES
General Description
The EMC2104 is an SMBus compliant fan controller with
up to five (up to 4 external and 1 internal) temperature
channels. The fan drivers can be operated using two
methods each with two modes. The methods include an
RPM based Fan Speed Control Algorithm and a direct
drive setting. The modes include manually programming
the desired settings or using the internal programmable
temperature look-up table to select the desired setting
based on measured temperature.
The temperature monitors offer 1°C accuracy (for
external diodes) with sophisticated features to reduce
errors introduced by series resistance and beta variation
of substrate thermal diode transistors commonly found
in processors.
The EMC2104 also includes a hardware programmable
temperature limit
S
and dedicated system shutdown
output for thermal protection of critical circuitry.
Datasheet
Features
Two Programmable Fan Control circuits.
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4-wire fan compatible
High speed PWM (26khz)
Low speed PWM (9.5Hz - 2240Hz)
Optional detection of aging fans
RPM based fan control algorithm
— 2% accuracy from 500RPM to 16k RPM
Temperature Look-Up Table
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Allows programmed fan response to temperature
1 to 4 thermal zones to control each fan driver
Controls fan speed or drive setting
Allows externally generated temperature data to control
fan drivers including two DTS channels
Up to Four External Temperature Channels
— Designed to support 45nm, 60nm, and 90nm CPUs
— Automatically detects and supports CPUs requiring the
BJT or Transistor models
— Resistance error correction
— 1°C accurate (60°C to 100°C)
— 0.125°C resolution
— Detects fan aging and variation
Applications
Notebook Computers
Embedded Applications
Projectors
Industrial and Networking Equipment
Up to three thermistor compatible voltage inputs
Hardware Programmable Thermal Shutdown
Temperature
— Cannot be altered by software
— 60°C to 122°C Range or 92°C to 154°C Range
Programmable High and Low Limits for all channels
3.3V Supply Voltage
SMBus 2.0 Compliant
— SMBus Alert compatible
Available in 20-pin QFN Package - Lead Free RoHS
compliant (4mm x 4mm)
SMSC EMC2104
DATASHEET
Revision 1.74 (05-08-08)
SMSC [ SMSC CORPORATION ]
