Rainbow-electronics MAX6640 User Manual

General DescriptionThe MAX6640 monitors its own temperature and oneexternal diode-connected transistor or the temperaturesof two external diode-connec

MAX6640stored in register 22h or 23h. Bit 0 of register 11h (fan1) and register 15h (fan 2) selects the behavior belowTMIN. If bit 0 is equal to zero,

MAX66402-Channel Temperature Monitor with DualAutomatic PWM Fan-Speed Controller______________________________________________________________________

MAX66402-Channel Temperature Monitor with DualAutomatic PWM Fan-Speed Controller12 ___________________________________________________________________

• D5: SMBus Timeout Disable. Writing a zeroenables SMBus timeout for prevention of bus lockup.When the timeout function is enabled, the SMBusinterface

MAX6640• D[3:2]: Temperature Channel(s) for Fan Control.Selects the temperature channel(s) that control thePWM output when the MAX6640 is in automatic

Fan 1 and 2 Configuration 2b (12h and 16h)The following registers select the tachometer step sizesand number of steps for step-size A to step-size Bsl

MAX6640Applications InformationFan-Drive CircuitsA variety of fan-drive circuit configurations can be usedwith the MAX6640 to control the fan’s speed.

4-Wire FansSome fans have an additional, fourth terminal thataccepts a logic-level PWM speed-control signal asshown in Figure 10. These fans require n

MAX6640Effect of Ideality FactorThe accuracy of the remote temperature measurementsdepends on the ideality factor (n) of the remote diode(actually a t

The transistor must be a small-signal type with a rela-tively high forward voltage; otherwise, the ADC inputvoltage range can be violated. The forward

MAX66402-Channel Temperature Monitor with DualAutomatic PWM Fan-Speed Controller2 ____________________________________________________________________

MAX66402-Channel Temperature Monitor with DualAutomatic PWM Fan-Speed Controller20 ___________________________________________________________________

MAX66402-Channel Temperature Monitor with DualAutomatic PWM Fan-Speed Controller______________________________________________________________________

MAX66402-Channel Temperature Monitor with DualAutomatic PWM Fan-Speed ControllerMaxim cannot assume responsibility for use of any circuitry other than

MAX66402-Channel Temperature Monitor with DualAutomatic PWM Fan-Speed Controller______________________________________________________________________

MAX66402-Channel Temperature Monitor with DualAutomatic PWM Fan-Speed Controller4 ____________________________________________________________________

MAX66402-Channel Temperature Monitor with DualAutomatic PWM Fan-Speed Controller______________________________________________________________________

MAX6640Detailed DescriptionThe MAX6640 monitors its own temperature and aremote diode-connected transistor or the temperaturesof two external diode-co

SMBus Digital InterfaceFrom a software perspective, the MAX6640 appears asa set of byte-wide registers. This device uses a stan-dard SMBus 2-wire/I2C™

MAX6640perature register read before the scheduled update.This allows enough time to read the main registerbefore it is updated, thereby preventing re

FAIL, the fan with a tachometer fault goes to full speed for2s in an attempt to restart the fan and then returns to theoriginal duty-cycle settings. R