3.3 V fixed reference in a three-pin SOT-23
It is designed for applications requiring a stable, low-noise reference voltage — think ADC references, DAC bias, or precision regulator setpoints in industrial and automotive environments. That combination means the output stays within a few millivolts of 3.3 V over temperature without external trimming. Supply current is 135 µA typical, making it suitable for always-on reference rails in battery-operated equipment.
Noise floor and output drive
Low-frequency noise is specified at 43 µVp-p over 0.1 Hz to 10 Hz, and 63 µVrms over 10 Hz to 10 kHz. For a 16-bit ADC with a 3.3 V reference, that noise contribution is well below 1 LSB, so it won't limit the converter's effective resolution in most industrial signal chains. The output can source or sink up to 10 mA. That's enough to bias a handful of op-amp inputs or a single ADC reference input, but not enough to power a load — plan a buffer if the reference rail needs to drive multiple converters or a long trace.
The base product number is REF3133, so other tolerance or temperature variants (REF3133AIDBZR, REF3133AIDBZT) share the same die and pinout.