OS The HE2021A33HPBR is a SOT89B-3 Linear Voltage Regulator (LDO), ROHS manufactured by HEERMICROS. This single output regulator is ideal for portable equipment applications due to its low voltage operation. It can deliver up to 3A of continuous current with an input voltage range of 2V to 20V. The output voltage range is adjustable from 1.2V to 15V. This device is equipped with over-voltage, over-temperature, under-voltage, current limit protection, and reverse capability with up to 33mV of dropout voltage. The regulator also offers excellent line and load transient response performance.