Recent LDO(low-dropout) regulator requires over-current protection and thermal protection circuits to satisfy the increase of integration and power density in regulator. Proposed LDO in this work consists of bandgap reference voltage circuit, and erro...
Recent LDO(low-dropout) regulator requires over-current protection and thermal protection circuits to satisfy the increase of integration and power density in regulator. Proposed LDO in this work consists of bandgap reference voltage circuit, and error amplifier in addition to the mentioned protection circuits. The over current protection circuit is found to eliminate the channel length modulation effects in transistors when load and line regulations occur. In order to supress thermal oscillation in LDO, the thermal protection circuit applies comparator which has a hysteresis characteristics. The circuit was designed by 0.18 ㎛ CMOS technology. The LDO output voltage is obtained to be 1.3 V with an input voltage of 1.8 V and the maximum output current of 10mA.