Fixed 3.3V LDO with 75dB PSRR — what it does for your rail
The LD1117V33-DG is a fixed-output 3.3V low-dropout linear regulator from STMicroelectronics, rated for 800mA continuous output current. Its 75dB PSRR at 120Hz makes it a strong candidate for post-switcher clean-up on analog or mixed-signal rails where ripple rejection matters more than efficiency. Dropout voltage is 1.2V maximum at full 800mA load. Quiescent current is 10 mA.
STMicroelectronics lists the LD1117V33-DG as Obsolete. The supplier device package is TO-220.
Built-in protection includes over-current and over-temperature shutdown. Maximum input voltage is 15V, so the part can be used on 5V, 9V, or 12V rails without issue, provided the dropout headroom is respected.