2.048V fixed reference — the ADC/DAC foundation
The REF5020IDR is a precision series voltage reference from Texas Instruments, delivering a fixed 2.048V output with ±0.05% initial accuracy and a 3 ppm/°C temperature coefficient across the full -40 to 125°C range. That 2.048V level is a natural fit for bipolar ADC input ranges (±2.048V) and for driving the reference input of successive-approximation or delta-sigma converters where the reference noise floor directly sets the system SNR.
Noise floor and drift — the specs that matter for converter performance
Output noise is specified at 3 µVp-p over the 0.1 Hz to 10 Hz band — the frequency range where 1/f noise dominates and where a precision ADC's reference input is most sensitive. A noisy reference here costs effective bits before the converter even sees the signal. The 3 ppm/°C drift means the reference voltage shifts less than 1.5 mV over the full temperature range, keeping the ADC transfer function stable across industrial thermal cycling. The series architecture (no load-dependent dropout) delivers 10 mA output current with a 1.2 mA quiescent supply current.