2.048 V fixed output, ±0.2% tolerance — the reference rail decision
The REF3020AIDBZRG4 is a Texas Instruments series voltage reference that delivers a fixed 2.048 V output with ±0.2% initial tolerance. That 2.048 V is a natural span for 12-bit ADCs with a 0–2.048 V input range — every LSB lands at exactly 500 µV, making the math clean and the system error budget predictable. The series topology means the load current comes from the input supply, not the reference output, so the output stays stable even when the load varies.
25 mA output, 50 µA supply — driving the ADC reference input
Rated for 25 mA continuous output current, this reference can drive the reference input of several successive-approximation ADCs simultaneously without an external buffer. The 50 µA quiescent supply current keeps the power budget tight in battery-powered or loop-powered designs — the reference itself draws less than the ADC's reference input current during conversion.
SOT-23-3 package — footprint and storage
Housed in a SOT-23-3 (TO-236-3, SC-59) surface-mount package, the REF3020AIDBZRG4 shares the same three-pin footprint as the rest of the REF3020 family. Store the reels in a dry cabinet — the SOT-23-3 body is not moisture-sensitive per JEDEC Level 1, but the tape and reel absorb humidity over long storage.