TC646

The TC646 is a switch mode fan speed controller for use with brushless DC motors. Temperature proportional speed control is accomplished using pulse width modulation(PWM). A thermistor (or other voltage output temperature sensor)connected to the VIN input furnishes the required control voltage of 1.25V to 2.65V(typical) for 0% to 100% PWM duty cycle. The TC646 automatically suspends fan operation when measured temperature (VIN) is below a user-programmed minimum setting (VAS). An integrated Start-Up Timer ensures reliable motor start-up at turn-on, coming out of Shutdown mode, or following a transient fault. In normal fan operation, a pulse train is present at SENSE, pin 5. The TC646 also features Microchip Technology's proprietary FanSense™ TM technology for increasing system reliability. A missing-pulse detector monitors this pin during fan operation. A stalled, open, or unconnected fan causes the TC646 to trigger its startup timer once. If the fault persists, the FAULT output goes low, and the device is latched in its Shutdown Mode. FAULT is also asserted if the PWM reaches 100% duty cycle, indicating a possible thermal runaway situation, although the fan continues to run. See the Applications section for more information and system design guidelines. The TC646 is packaged in a space-saving 8-pin plastic DIP, MSOP or SOIC package and is available in the industrial temperature range.

Features
  • Temperature Proportional
  • Fan Speed for Acoustic Control and Longer Fan Life
  • Efficient PWM Fan Drive
  • 3.0V to 5.5V Supply Range
  • Fan Voltage Independent of TC646 Supply Voltage Supports Any Fan Voltage!
  • Supports Any Fan Voltage!
  • FanSense™ TM Fault Detection Circuits Protect Against Fan Failure and Aid
  • System Testing
  • Automatic Shutdown Mode for "Green" Systems
  • Supports Low Cost NTC/PTC Thermistors
Parameter
Parameter Name Value Value
Device Description Fan Manager Fan Manager
Typical Accuracy (°C) Depends on external thermistor Depends on external thermistor
Over Temp Alert yes yes
Max. Supply Current (µA) 1000 1000
Max. Accuracy @ 25°C (°C) Depends on external thermistor Depends on external thermistor
Fan Sense Yes Yes
External Temp Input Yes Yes
Auto Shutdown Yes Yes
High/Low PWM Freq Low Low
Temp Range (°C) -40 to +85 -40 to +85
Vcc Range (V) +3.0 to +5.5 +3.0 to +5.5
Documents
TC646 DatasheetData Sheets02/05/2013368KB
AN770 - Linear Voltage Fan Speed Control Using Microchip?s TC64x Family (TC642, TC646, TC648)AppNote07/27/2004203KB
AN771 - Suppressing Acoustic Noise in PWM Fan Speed Control SystemsAppNote07/27/2004276KB
TB063 - An Integrated Fan Speed Control Solution Can Lower System Costs, Reduce Acoustic Noise, Power Consumption and Enhance System ReliabilityAppNote02/24/2003204KB
Analog & Interface Guide (Volume 2)Brochures10/11/20051067KB
Quick Guide to Microchip Development ToolsBrochures10/15/201411223KB
Fan Control Function Pack Design GuideProduct Line Documents08/23/2006162KB
Fan Management Solutions Product OverviewProduct Line Documents08/23/200687KB
Fan Speed Controller and Fan Fault Detector FamilyProduct Line Documents05/13/2003245KB
Analog & Interface Product Selector GuideProduct Line Card03/21/20164116KB
8-Pin SOIC/MSOP/TSSOP/DIP Evaluation Board User's GuideUser Guides01/24/20061367KB
TC64X/TC64XB Fan Control Evaluation Board User's GuideUser Guides11/24/2003360KB
Thermistor Value Calculator with Solver for the TC64x FamilyUser Guides11/24/2003130KB
Thermistor Value Calculator without Solver for the TC64x FamilyUser Guides11/24/2003107KB
Ordering Information
Part NumberLeadsPackage TypeTemp RangePacking1+26+100+1000+5000+
TC646EOA8SOIC-40C to +85CTUBE1.521.271.151.111.10
TC646EOA7138SOIC-40C to +85CT/R1.521.271.151.111.10
TC646EUA8MSOP-40C to +85CTUBE1.401.161.061.021.01
TC646EUA7138MSOP-40C to +85CT/R1.401.161.061.021.01
TC646VOA8SOIC0C to +85CTUBE1.481.231.121.081.07
TC646VOA7138SOIC0C to +85CT/R1.481.231.121.081.07
TC646VPA8PDIP0C to +85CTUBE1.551.291.181.141.12
TC646VUA8MSOP0C to +85CTUBE**********
Similar Devices
ProductDescriptionTypical Accuracy (º)Temp RangePrice5K
EMC2101±0.5-40 - +125$0.79
EMC2300±0.250 - 70$1.24
EMC6D102±0.250 - 70$1.63
EMC6D103±0.250 - 70$1.80
EMC6D103S±0.250 - 70$1.80
EMC6W201±0.250 - 70$2.19
TC642Fan ManagerDepends on external thermistor-40 - +85$1.02
TC642BFan ManagerDepends on external thermistor-40 - +85$0.84
TC646Fan ManagerDepends on external thermistor-40 - +85$1.02
TC646BFan ManagerDepends on external thermistor-40 - +85$0.84
TC647Fan ManagerDepends on external thermistor-40 - +85$0.94
TC647BFan ManagerDepends on external thermistor-40 - +85$0.84
TC648Fan ManagerDepends on external thermistor-40 - +85$0.85
TC648BFan ManagerDepends on External Thermistor-40 - +85$0.79
TC649Fan ManagerDepends on external thermistor-40 - +85$0.94
TC649BFan ManagerDepends on external thermistor-40 - +85$0.84
TC650Fan Manager1-40 - +125$1.26
TC651Fan Manager1-40 - +125$1.08
TC652Fan Manager1-40 - +125$1.36
TC653Fan Manager1-40 - 125$1.36
TC654Dual SMBus Fan ManagerDepends on external thermistor-40 - +85$1.43
TC655Dual SMBus Fan ManagerDepends on external thermistor-40 - +85$1.53
TC664Single SMBus Fan ManagerDepends on external thermistor-40 - +85$1.27
TC665Single SMBus Fan ManagerDepends on external thermistor-40 - +85$1.31
TC670Predictive Fan Fault DetectorN/A-40 - +85$0.94
RoHS Information
PartNumberDeviceWeightShippingWeightLeadCountPackageTypePackageWidthSolderCompositionJEDECIndicatorRoHSChinaEFUP
TC646VPA0.4867000.9000008PDIP.300inMatte Tine3
TC646BEPA0.4867000.9000008PDIP.300inMatte Tine3
TC646EOA0.0780000.1600008SOIC.150In(3.90mm)Matte Tine3
TC646EOA7130.0780000.2303038SOIC.150In(3.90mm)Matte Tine3
TC646BEOA0.0780000.1600008SOIC.150In(3.90mm)Matte Tine3
TC646BEOA7130.0780000.2303038SOIC.150In(3.90mm)Matte Tine3
TC646VOA0.0780000.1600008SOIC.150In(3.90mm)Matte Tine3
TC646VOA7130.0780000.2303038SOIC.150In(3.90mm)Matte Tine3
TC646EUA0.0256000.0700008MSOP3x3mmMatte Tine3
TC646EUA7130.0256000.2156008MSOP3x3mmMatte Tine3
TC646VUA0.0256000.0700008MSOP3x3mmMatte Tine3
TC646VUA7130.0256000.2156008MSOP3x3mmMatte Tine3
TC646BEUA7130.0256000.2156008MSOP3x3mmMatte Tine3
TC646BEUA0.0256000.0700008MSOP3x3mmMatte Tine3
TC646 Datasheet TC646
TC646 Datasheet TC646
AN770 TC649B
AN771 TC649B
TB063 TC649B
Analog & Interface Guide (Volume 2) MCP23S08
Quick Guide to Microchip Development Tools ENC28J60
Fan Control Function Pack Design Guide TC670
Fan Management Solutions Product Overview TC670
Fan Speed Controller and Fan Fault Detector Family TC665
Analog & Interface Product Selector Guide ENC624J600
8-Pin SOIC/MSOP/TSSOP/DIP Evaluation Board User's Guide SOIC8EV
TC64X/TC64XB Fan Control Evaluation Board User's Guide TC649B