In this study, we have fabricated a three branches vertical Hall sensor for detecting three phases rotation informations of miniaturized brushless motor. The sensor gives three position signals phase shifted by $120^{circ}$, corresponding to the motor driving signals. The branch has one Hall output and one input each other. The central part acts as common driving input. Sensor has branch width of $150{mu}m$ and distance from central electrode to Hall electrode of $100{mu}m$. The sensitivity of sensor is 250 V/$A{cdot}T$ at magnetic field of 0.1 T. It has also showed three sine waves of Hall voltages with $120^{circ}$ phase over a $360^{circ}$ rotation. A packaged sensing part are $2{ imes}2mm^{2}$ and has been successfully tested on a motor rotation at a speed up to 60,000 rpm.