DESCRIPTION
EUM6270 is suitable for variable speed control motor for personal computer’s power supply radiation fans and CPU coolers. The EUM6270 functions include PWM control mode, minimum speed mode, fan tachometer, soft switching, lock protection, auto restart, current limit and Hall Bias. PWM mode controls internal power devices in low noise and low vibration fashion. Minimum speed mode makes the lowest speed of motor settable. If the motor is stalled by external force or obstacles, overdrive current may incur coil overheat and burning. To prevent motor from overheating, the lock protection circuit will shut down the internal power devices for a few seconds after motor is locked up. Then auto restart circuit resumes to power up. The protection and power up time are settable by external capacitor. When the voltage drop between VCC and VM is higher than 0.48V (Typ.), the EUM6270 outputs will be turned off by current limit function. EUM6270 has motor rotation speed feedback (FG) output and Hall sensor bias output.
Eutech Microelectronics