2.5 V reference — the noise floor and drift are the real specs
The REF5025ID is a Texas Instruments precision series voltage reference that delivers a fixed 2.5 V output with ±0.05% initial accuracy. The headline numbers here are the 3 µVp-p low-frequency noise (0.1 Hz to 10 Hz) and the 3 ppm/°C temperature coefficient — these two specs determine whether this reference can support a 16-bit or 18-bit ADC without the reference noise eating into the system's SNR budget.
Noise, drift, and output drive — what each rating means for your BOM
The 3 µVp-p noise over 0.1 Hz to 10 Hz is the figure that matters for precision measurement — a 16-bit ADC with a 2.5 V input span has an LSB of roughly 38 µV, so this reference contributes less than 0.1 LSB of peak-to-peak noise at the low end. The 3 ppm/°C drift means the output shifts about 7.5 µV per 10 °C change, which adds about 0.2 LSB error over a typical industrial temperature swing. The 10 mA output current is enough to drive the reference input of multiple ADCs or a small sensor excitation bridge, but not a heavy load — budget the load current carefully to stay within the 10 mA ceiling.