EMC2104_11 Datasheet, PDF (1/99 Pages) SMSC Corporation – Dual RPM-Based PWM Fan Controller with Hardware Thermal Shutdown

EMC2104
Dual RPM-Based PWM Fan
Controller with Hardware
Thermal Shutdown
PRODUCT FEATURES
Datasheet
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 limitS and dedicated system shutdown
output for thermal protection of critical circuitry.
Applications
„ Notebook Computers
„ Embedded Applications
„ Projectors
„ Industrial and Networking Equipment
Features
„ Two Programmable Fan Control circuits
— 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
— 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
„ 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 1.78 (02-28-11)