1.25V reference with ±0.2% initial accuracy — the precision floor for your ADC rail
The REF3112AIDBZR is a 1.25V fixed-output series voltage reference from Texas Instruments, specified with a ±0.2% initial tolerance and a 20ppm/°C temperature coefficient.
Noise and supply current — what they mean for a precision chain
Output noise is 17µVp-p from 0.1 Hz to 10 Hz, and 24µVrms from 10 Hz to 10 kHz. For a 12-bit ADC with a 1.25V reference, the peak-to-peak noise contributes roughly 0.5 LSB of flicker noise — acceptable for most industrial measurements, but a 16-bit design would need a lower-noise reference or digital averaging. Supply current is 135µA typical, low enough to leave the reference powered continuously in a battery-operated sensor node without draining the cell overnight.
SOT-23-3 footprint and supply range
Housed in a SOT-23-3 package (also referred to as TO-236-3 / SC-59), the REF3112AIDBZR takes up minimal board area and is a direct fit for precision-voltage rails on mixed-signal PCBs. The input voltage range is 1.8V to 5.5V, so it can be powered from a 3.3V or 5V supply without a separate regulator. Output current is rated at 10 mA — enough to bias a single ADC reference input or a small resistive divider, but not intended to drive multiple converter channels or a heavy load.