EUM6808 ds6808 ver0.2 june 2013 1 pwm fan motor driver with slope control description EUM6808 is a fan motor driver for brushless dc fan motor. it integrates three types speed control mode s soft switched output, lock protection, hall bias, f g output, shutdown mode, quick restart and tsd. with these modes and functions, EUM6808 can not only be applied to dc fans which require different speed curves, but also be applied to nb and other portabl e equipments which require silence and low power dissipation. the three types speed control modes are pwm control mode, vcc control mode with slope adjustable, normal vcc control mode. soft switched output drive s dc fan in low noise and low vibration. if a dc fan is stalled by the external force or obstacles, overdri ve current may incur coil overheat and burning. to prevent motor from overheating, the lock protection circuit shuts down the internal power devices for a few seconds after the motor lock is detected. then the auto restart circuit resumes to power up the internal po wer devices. EUM6808 has built in hall ic bias output, motor rotation speed feedback (fg). with its shutdo wn mode and quick restart, EUM6808 consumes little power dissipation during shutdown time and can be started at once regardless of lock detection time. features single-phase full-wave driver system three speed control mode pwm control mode vcc control mode with slope adjustable normal vcc control mode soft switched drive for silent application lock detection and automatic restart shutdown mode and quick restart low standby current (pwm = l) fg output hall bias output thermal shutdown protection available in udfn-10 and msop-10 package rohs compliant and 100% lead (pb)-free halogen-free applications nb cooling fan silent fan motor application circuit figure 1. pwm control mode
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