This document describes the ADR440/ADR441/ADR443/ADR444/ADR445, which are ultralow noise, LDO XFET voltage references with current sink and source. They have ultralow noise and temperature coefficient, making them suitable for precision data acquisition systems, high resolution data converters, battery-powered instrumentation, industrial process control systems, and more.
The ADR44x family of XFET voltage references offers ultralow noise (0.1 Hz to 10 Hz) and superb temperature stability, with A‑grade parts achieving 10 ppm/°C and B‑grade parts 3 ppm/°C. They operate from 3 V to 18 V supply voltage, feature a low dropout of 500 mV, and can source up to +10 mA or sink up to –5 mA.
These devices are intended for precision data‑acquisition systems, high‑resolution converters, battery‑powered instrumentation, medical instruments, and industrial process control. The series is available in 8‑lead SOIC and MSOP packages and is rated for –40 °C to +125 °C operation.
| Noise (0.1 Hz‑10 Hz) | 1 pV p‑p (ADR440) to 2.25 µV p‑p (ADR445) |
|---|---|
| Temperature Coefficient | A grade: 10 ppm/°C, B grade: 3 ppm/°C |
| Dropout Voltage | 500 mV |
| Supply Voltage Range | 3 V to 18 V |
| Output Current Capability | +10 mA source, –5 mA sink |
| Operating Temperature Range | –40 °C to +125 °C |
| Initial Accuracy (A grade) | 3 mV (0.15 %) |
| Short‑Circuit Duration | Indefinite |
The ADR440 operates from 3 V to 18 V.
The ADR445 has an output noise of 2.25 µV p‑p from 0.1 Hz to 10 Hz.
The device can sustain an indefinite short‑circuit to ground.
A‑grade parts have 10 ppm/°C and B‑grade parts have 3 ppm/°C.