Fixed 0.8V LDO for low-voltage rails
The MCP1725T-0802E/SN is a fixed-output low-dropout linear regulator from Microchip Technology, delivering 500 mA at 0.8 V from a single positive supply. It is designed for applications that need a clean, regulated 0.8 V rail — common in modern digital cores, FPGAs, and low-voltage ASICs — where the input voltage can go as high as 6 V. The dropout voltage is a maximum of 0.35 V at the full 500 mA load, meaning the input rail needs to stay above about 1.15 V to maintain regulation. That 200 mV headroom is the practical margin a board designer must budget for line transients and ripple.
PSRR and noise rejection
Power-supply rejection ratio is 60 dB at 100 Hz — this tells you how well the regulator attenuates low-frequency ripple from the upstream supply. For a 100 mV p-p ripple at 100 Hz on the input, the output sees roughly 100 µV p-p. That matters when the 0.8 V rail feeds a sensitive PLL or ADC reference. Quiescent current is 220 µA typical — the regulator's own draw is modest enough for battery-powered or always-on subsystems, though not as aggressive as a micropower LDO. The enable pin lets you shut down the output entirely when the rail is not needed.
Protection and control for reliable operation
Built-in protection includes over-temperature shutdown, short-circuit current limiting, and under-voltage lockout (UVLO). The UVLO prevents the output from turning on until the input voltage is high enough to guarantee regulation — avoids brownout glitches during power-up sequencing. A Power Good output flag signals when the output voltage is within regulation, useful for sequencing multiple rails or resetting a microcontroller after the supply settles. The enable pin provides a logic-level on/off control.
Package and temperature grade
The 'T' suffix indicates tape-and-reel packaging; cut-tape options are also available for prototype or low-volume builds.