EMC2305 Multiple RPM-Based PWM Fan Controller for Five Fans Datasheet PRODUCT FEATURES General Description Features Five Programmable Fan Control circuits (EMC2305) The EMC2305 is an SMBus compliant fan controller with 4-wire fan compatible up to five independently controlled PWM fan drivers. High speed PWM (26 kHz) Each fan driver is controlled by a programmable Low speed PWM (9.5Hz - 2240 Hz) frequency PWM driver and Fan Speed Control algorithm Optional detection of aging fans that operates in either a closed loop fashion or as a Fan Spin Up Control and Ramp Rate Control directly PWM-controlled device. Alert on Fan Stall Up to 3 Selectable Default Fan Speeds The closed loop Fan Speed Control algorithm (FSC) has Watchdog Timer the capability to detect aging fans and alert the system. RPM-based fan control algorithm It will likewise detect stalled or locked fans and trigger 0.5% accuracy from 500 RPM to 16k RPM (external an interrupt. crystal oscillator) 1% accuracy from 500 RPM to 16k RPM (internal clock) Additionally, the EMC2305 offers a clock output so that multiple devices may be chained and slaved to the SMBus 2.0 Compliant Up to 6 selectable SMBus addresses same clock source for optimal performance in large SMBus Alert compatible distributed systems. CLK Pin can provide a clock source output Applications Available in a 16-pin 4mm x 4mm QFN Lead-free Servers RoHS Compliant package Projectors Industrial and Networking Equipment Notebook Computers Block Diagram CLK TACH1 TACH2 Tachometer Tach TACH3 Limit Measurement Registers TACH4 ADDR SEL SMBus TACH5 SMCLK Slave PWM1 Fan Speed Control Algorithm SMDATA Protocol PWM2 Fan Speed Control Algorithm ALERT PWM PWM3 Fan Speed Control Algorithm Drivers PWM4 Fan Speed Control Algorithm PWM5 Fan Speed Control Algorithm SMSC EMC2305 DATASHEET Revision 1.3 (05-18-11) Multiple RPM-Based PWM Fan Controller for Five Fans Datasheet Order Number: ORDERING NUMBER PACKAGE FEATURES EMC2305-1-AP-TR 16-pin QFN (Lead-free Five RPM-based fan speed control RoHS compliant) algorithms This product meets the halogen maximum concentration values per IEC61249-2-21 For RoHS compliance and environmental information, please visit www.smsc.com/rohs 80 ARKAY DRIVE, HAUPPAUGE, NY 11788 (631) 435-6000 or 1 (800) 443-SEMI Copyright 2011 SMSC or its subsidiaries. All rights reserved. Circuit diagrams and other information relating to SMSC products are included as a means of illustrating typical applications. Consequently, complete information sufficient for construction purposes is not necessarily given. Although the information has been checked and is believed to be accurate, no responsibility is assumed for inaccuracies. SMSC reserves the right to make changes to specifications and product descriptions at any time without notice. Contact your local SMSC sales office to obtain the latest specifications before placing your product order. The provision of this information does not convey to the purchaser of the described semiconductor devices any licenses under any patent rights or other intellectual property rights of SMSC or others. All sales are expressly conditional on your agreement to the terms and conditions of the most recently dated version of SMSC s standard Terms of Sale Agreement dated before the date of your order (theTerms of Sale Agreemen). The product may contain design defects or errors known as anomalies which may cause the product s functions to deviate from published specifications. Anomaly sheets are available upon request. SMSC products are not designed, intended, authorized or warranted for use in any life support or other application where product failure could cause or contribute to personal injury or severe property damage. Any and all such uses without prior written approval of an Officer of SMSC and further testing and/or modification will be fully at the risk of the customer. Copies of this document or other SMSC literature, as well as the Terms of Sale Agreement, may be obtained by visiting SMSCs website at