3 V fixed reference for precision ADC and sensor biasing
The REF3130AIDBZRG4 is a 3 V precision series voltage reference from Texas Instruments, delivering a fixed 3 V output with ±0.2% initial accuracy and a 20 ppm/°C temperature coefficient. It is designed to bias precision ADCs, DACs, and sensor signal chains in industrial and automotive environments spanning -40°C to 125°C.
Noise floor and drift — what they mean for ADC resolution
Low-frequency noise is specified at 39 µVp-p over 0.1 Hz to 10 Hz, and broadband noise at 57 µVrms over 10 Hz to 10 kHz. For a 12-bit ADC with a 3 V reference, the LSB is 732 µV — the reference noise contributes less than 8% of one LSB, leaving headroom for system noise. The 20 ppm/°C drift translates to 60 µV shift over a 100°C swing, which a 12-bit system absorbs without calibration; a 16-bit system with 46 µV LSBs would need periodic trim. The 10 mA output current capability is enough to drive the reference input of most SAR ADCs and the external REF pin of a microcontroller's ADC, but not enough to power a sensor bridge directly — that load belongs on a separate regulator.
Input headroom and dropout margin
Input voltage range runs from 3.05 V to 5.5 V. On a 3.3 V rail, the 300 mV dropout is comfortable; on a 5 V rail, the 2 V headroom keeps the series pass element in its linear region across load and temperature. The series architecture means no external resistor is needed — just a 0.1 µF bypass cap on the input and a 1 µF cap on the output for stability.
SOT-23-3 footprint and tape-and-reel delivery
Housed in a 3-pin SOT-23-3 (TO-236-3 / SC-59) package, the REF3130AIDBZRG4 occupies under 3 mm² of board area.