FM5001L handheld 3-speed fan dedicated IC
    FM5001L is a power management IC that integrates lithium battery charging management, lithium battery protection, DC-DC boost current limiting, and 3-speed adjustable air volume fan drive functions; Specially designed for portable fans powered by lithium batteries.
    FM5001L integrates charging methods including trickle charging, constant current charging, and constant voltage charging throughout the entire process, with charging indicators and full charge indicator lights; Supports fan drive function, built-in 3-speed adjustable air volume control, and supports discharge LED indication; When the battery voltage is less than 2.9V, the FM5001L system enters an undervoltage state, and the entire system current is 30uA; Built in constant current charging current of 600mA.
    FM5001L has multiple protection designs, including load overcurrent protection, anti backflow protection during charging, short circuit anti locking, soft start protection, lithium battery over discharge protection, over temperature and under voltage protection, etc.
    FM5001L integrates a fan control and drive circuit with adjustable air volume in three levels; When there is no charger connected, press the SWCH1 button to control the change in air volume. Press the button once to change the air volume by one level, and the air volume will change from weak to strong. When the VOUT pin has a boost output, the fan light is on. The output voltage VFAN of the VOUT terminal is 4.5V for the first level, 5.4V for the second level, and 6.4V for the third level (with a voltage deviation of ± 0.3V between chips in each level). When a charger is connected, short press SWCH1, the fan will only work in gear 1, the fan light will turn on, and the charging light will turn on.