Tiny Cooling Fan high- and low-side drivers

"Tiny Cooling Fan" high-side driver circuit is slightly more complex, the benefit is the negative side of the fan may be grounded, speed and alarm sensors have the same reference ground, and easy interface. Low-side driver does not require level shifting, but the speed and alarm sensors need level conversion circuit. Then "Tiny Cooling Fan" positive terminal is generally maintained at a constant voltage, and the negative terminal voltage can be controlled and regulated, therefore the reference point speed and alarm sensors easy to change, requiring level conversion circuit. "Tiny Cooling Fan" speed control and independent of temperature measurement, so this is an open-loop control system, there is no stability problems.