Fixed 2.5V shunt reference in SOT-23-3
The STMicroelectronics TS824ILT-2.5 is a fixed 2.5V shunt voltage reference in a three-pin SOT-23-3 package. It delivers a regulated 2.5V output with ±1% initial tolerance and a temperature coefficient of 50 ppm/°C, making it a straightforward drop-in for board-level biasing or ADC reference duties where a precision bandgap isn't required. The shunt architecture means it behaves like a two-terminal Zener — you bias it through a series resistor from a higher supply rail, and the 60 µA minimum cathode current keeps it in regulation down to light loads.
The 15 mA output current rating sets the maximum load the reference can sink while maintaining regulation. In practice, you size the series resistor so the total current (load plus cathode) stays under 15 mA over the full input voltage range. The 60 µA cathode current is the minimum bias needed to keep the shunt in its active region — if the load drops below that, the reference may drop out of regulation. For a typical 2.5V reference feeding a microcontroller ADC with a few hundred µA load, the 60 µA floor is easy to meet, but a design with a very light or intermittent load should include a dummy resistor to guarantee minimum bias.
Temperature range and package fit
The SOT-23-3 footprint (also known as TO-236-3 or SC-59) is a standard small-signal package — same land pattern as many general-purpose transistors and diodes, so board layout is straightforward.