View lr312 lr315 lr318 lr328 lr329 lr333-series datasheet:

UNISONIC TECHNOLOGIES CO., LTD LR3XXYYB CMOS IC 150mA 2CH LDO REGULATOR  DESCRIPTION The UTC LR3XXYYB are CMOS voltage regulator ICs that have 4 high output voltage accuracy, low dropout, low supply current, and 5 6 high ripple rejection. Every voltage regulator IC of UTC LR3XXYYB series consists of an error amplifier, a voltage reference unit, a 3 2 current limit circuit, resistors for setting output voltage, and a chip 1 enable circuit. SOT-26 Due to built-in transistor with low ON resistance and a chip enable function these ICs perform with low dropout voltage prolongs the battery life of each system. The load transient response and line transient response of the UTC LR3XXYYB Series are excellent, so these ICs are suitable for hand-held communication