DC motor / FAN. It integrates a H-bridge MOS driver, a high sensitivity hall-effect sensor, a digital control logic with internal clock for rotor locked, tachometer or alarm output logic and motors’ speed control functions only in TS826 package, which make the motors’ PCBs(printed circuit boards) design easy and fabricate the small and tiny size DC motors or FANs as simply as possible. For safety, Lock-shutdown function would turn the IC’s internal drivers off avoiding over-heat when the rotor is locked, and IC will try to re-start the rotor’s torque after the time of these drivers’ shutdown. FD125K/Sf is built-in the tachometer signal or alarm signal output function, the external system could be readout the motor’s speed (FG) or rotation status (RD) from the signal pin of FD125K/Sf IC. Thermal-shutdown protection (TSD) ensures the internal drivers of IC are operating under a safe operating temperature range. There are two variable speed control modes in FD125K/Sf, the programmable PWM duty cycle and DC voltage level to the same pin of IC.