The S-1155 Series, developed based on CMOS technology, is a positive voltage regulator with a super low dropout voltage, high output voltage accuracy, and low current consumption. The S-1155 Series provides the very small dropout voltage and the large output current due to the built-in transistor with low on-resistance. The overcurrent protector prevents the load current from exceeding the capacitance of output transistor. The thermal shutdown circuit prevents damage caused by heat, the rush current control circuit limits the excessive rush current during start-up. The ON/OFF circuit ensures longer battery life. Various capacitors, also small ceramic capacitors, can be used for this IC more than for the conventional regulator ICs which have CMOS technology. The small package SOT-89-5 enables high-density mounting.