The Texas Instruments REF5045AIDG4 is a precision series voltage reference that delivers a fixed 4.5 V output with ±0.1% initial accuracy and an 8 ppm/°C temperature coefficient. The 3 µVp-p low-frequency noise spec (0.1 Hz to 10 Hz) is the number that matters for a 16-bit or 20-bit ADC — it sets the noise floor below the converter's LSB, so the reference does not become the dominant error source in the measurement path.
Output drive and supply headroom
The REF5045AIDG4 can source up to 10 mA of output current, which is enough to bias a reference buffer or multiple ADC reference inputs on the same rail. The input voltage range of 4.7 V to 18 V gives the designer headroom to run the reference from a 5 V or 12 V rail without a separate LDO. Quiescent supply current is 1.2 mA typical, so the reference adds minimal overhead to the system power budget — relevant for multi-channel data-acquisition boards where every milliamp counts.