Document
RPM-Based Fan Controller with Hardware Thermal Shutdown
EMC2103
PRODUCT FEATURES
Datasheet
General Description
The EMC2103 is an SMBus compliant fan controller with up to up to 3 external and 1 internal temperature channels. The fan driver can be operated using two methods each with two modes. The methods include an RPM based Fan Speed Control Algorithm and a direct PWM 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 ±0.5°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 EMC2103 also includes a hardware programmable temperature limit and dedicated system shutdown output for thermal protection of critical circuitry.
Applications Notebook Computers Projectors Graphics Cards Industrial and Networking Equipment
Features
Programmable Fan Control circuit — 4-wire fan compatible — High and low frequency PWM
RPM based fan control algorithm — 2.5% accuracy from ~500RPM to 16k RPM — Detects fan aging and variation
Temperature Look-Up Table — Allows programmed fan response to temperature — Controls fan speed or PWM drive setting — Allows externally set temperature data to drive fan — Supports DTS data from CPU
Up to Three External Temperature Channels (EMC2103-2 and EMC2103-4 only) — Supports 45nm, 60nm, and 90nm CPU diodes — Automatically detects and supports CPUs requiring BJT or Transistor models — Resistance error correction — Supports discrete transistors (i.e. 2N3904) — ±0.5°C accurate (60°C to 125°C) — 0.125°C resolution
Hardware Programmable Thermal Shutdown Temperature — Cannot be altered by software — 65°C to 127°C Range
Programmable High and Low Limits for all channels
Internal Temperature Monitor — ±1°C accuracy — 0.125°C resolution
3.3V Supply Voltage
SMBus 2.0 Compliant — SMBus Alert compatible
Two dedicated GPIOs (EMC2103-2 and EMC2103-4 only)
Available in 12-pin, QFN RoHS Compliant Package (EMC2103-1) or 16-pin, QFN RoHS Compliant Package (EMC2103-2 and EMC2103-4)
2013 Microchip Technology Inc.
DS0005250A-page 1
RPM-Based Fan Controller with Hardware Thermal Shutdown Datasheet
ORDER NUMBERS:
ORDERING NUMBER EMC2103-1-KP-TR
EMC2103-2-AP-TR
EMC2103-4-AP-TR
PACKAGE 12-pin, QFN ROHS Compliant
16-pin, QFN ROHS Compliant
16-pin, QFN ROHS Compliant
FEATURES
One external diode, RPM based Fan Speed Control Algorithm, High Frequency PWM driver, HW Thermal / Critical shutdown, EEPROM Load disabled
Up to three external diodes, RPM based Fan Speed Control algorithm, High Frequency PWM driver, HW Thermal / Critical shutdown, 2 GPIOs, EEPROM Load disabled
Up to three external diodes, RPM based Fan Speed Control algorithm, High Frequency PWM driver, HW Thermal / Critical shutdown, 2 GPIOs, EEPROM Load enabled
REEL SIZE IS 4,000 PIECES This product meets the halogen maximum concentration values per IEC61249-2-21
DS0005250A-page 2
2013 Microchip Technology Inc.
RPM-Based Fan Controller with Hardware Thermal Shutdown
Datasheet
Table of Contents
Chapter 1 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Chapter 2 Pin Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Chapter 3 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.1 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.2 SMBus Electrical Specifications (Client Mode). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.3 EEPROM Loader Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Chapter 4 Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.1 System Management Bus Interface Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.2 Write Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.3 Read Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.4 Send Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.5 Receive Byte. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.6 Alert Response Address . . . . . . . . . . . . . . . .