Fixed 2.5 V rail for always-on and low-noise supplies
The TC1185-2.5VCT713 is a fixed-output 2.5 V LDO from Microchip, delivering up to 150 mA continuous current. Quiescent current is 80 µA typical, making it suitable for battery-powered circuits where the regulator itself should not dominate the standby budget. The enable pin lets a microcontroller or switch pull the output to near-zero draw when the rail is not needed.
PSRR and noise rejection in the signal chain
Power-supply rejection ratio is 64 dB at 1 kHz. This means a 100 mV ripple on the input at 1 kHz is attenuated to roughly 63 µV at the output — enough to keep a clean analog rail when the upstream supply is a switching converter running at a few hundred kHz. The 64 dB figure is specified at 1 kHz; PSRR typically rolls off at higher frequencies. For a 2 MHz switcher, expect less rejection — plan a post-filter if the load is an ADC reference or a sensitive analog front-end.
Temperature range and protection for industrial environments
Operating temperature spans -40 °C to +125 °C, covering the industrial and extended-temperature range. The SOT-23-5 package (SC-74A) is a standard five-pin small-outline footprint, with the thermal pad on the die flag — board copper area under the package sets the effective thermal resistance. Built-in over-current and over-temperature protection eliminate the need for an external sense resistor or thermal shutdown circuit. The regulator folds back current during a fault and recovers automatically when the condition clears.