EMC2305

The EMC2305 is an SMBus compliant fan controller with up to five independently controlled PWM fan drivers. Each fan driver is controlled by a programmable frequency PWM driver and Fan Speed Control algorithm that operates in either a closed loop fashion or as a directly PWM-controlled device.

The closed loop Fan Speed Control algorithm (FSC) has the capability to detect aging fans and alert the system. It will likewise detect stalled or locked fans and trigger an interrupt.

Additionally, the EMC2305 offers a clock output so that multiple devices may be chained and slaved to the same clock source for optimal performance in large distributed systems.

Features
  • Five Programmable Fan Control circuits 4-wire fan compatible High speed PWM (26 kHz) Low speed PWM (9.5Hz - 2240 Hz) Optional detection of aging fans Fan Spin Up Control and Ramp Rate Control Alert on Fan Stall Up to 3 Selectable Default Fan Speeds
  • 4-wire fan compatible
  • High speed PWM (26 kHz)
  • Low speed PWM (9.5Hz - 2240 Hz)
  • Optional detection of aging fans
  • Fan Spin Up Control and Ramp Rate Control
  • Alert on Fan Stall
  • Up to 3 Selectable Default Fan Speeds
  • Watchdog Timer
  • RPM-based fan control algorithm 0.5% accuracy from 500 RPM to 16k RPM (external crystal oscillator) 1% accuracy from 500 RPM to 16k RPM (internal clock)
  • 0.5% accuracy from 500 RPM to 16k RPM (external crystal oscillator)
  • 1% accuracy from 500 RPM to 16k RPM (internal clock)
  • SMBus 2.0 Compliant Up to 6 selectable SMBus addresses SMBus Alert compatible
  • Up to 6 selectable SMBus addresses
  • SMBus Alert compatible
  • CLK Pin can provide a clock source output
  • Available in a 16-pin 4mm x 4mm QFN RoHS Compliant package
  • Servers
  • Projectors
  • Industrial and Networking Equipment
  • Notebook Computers
Parameter
Parameter Name Value Value
comments Multi-Fan Speed Controller Multi-Fan Speed Controller
# Fans Drivers 5 5
PWM/Linear Control PWM PWM
Typical Accuracy N/A N/A
Max Accuracy N/A N/A
Maximum Temperature Range -40 to 125 -40 to 125
Vcc Range (V) 3.0 to 3.6 3.0 to 3.6
SMBus Alert Yes Yes
Voltage Monitors N/A N/A
Documents
EMC2305 Multiple RPM-Based PWM Fan Controller for Five Fans Data SheetData Sheets05/18/2011806KB
AN17.4 - RPM to TACH Counts ConversionAppNote05/05/2009447KB
AN18.15 - PCB Design Guidelines for QFN and DQFN PackagesAppNote10/16/2014205KB
EMC2305 Multiple RPM-Based PWM Fan Controller for Five Fans Data BriefProduct Briefs05/18/2011197KB
EMC2305 Library Part, Object Library FileSchematics02/07/20096KB
EMC2305 Reference Design Schematic, PDFSchematics02/19/200923KB
Ordering Information
Part NumberLeadsPackage TypeTemp RangePacking1+26+100+1000+5000+
EMC2305-1-AP-TR16QFN-40C to +125CT/R1.861.551.411.361.35
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RoHS Information
PartNumberDeviceWeightShippingWeightLeadCountPackageTypePackageWidthSolderCompositionJEDECIndicatorRoHSChinaEFUP
EMC2305-1-AP-TR0.0417000.21212116QFN4x4x0.9mmMatte Tine3
EMC2305 Multiple RPM-Based PWM Fan Controller for Five Fans Data Sheet EMC2305
AN17.4 EMC2305
AN18.15 LAN9220
EMC2305 Multiple RPM-Based PWM Fan Controller for Five Fans Data Brief EMC2305
EMC2305 Reference Design Schematic, PDF EMC2305