The AD704 is a quad, low power bipolar op amp that has the low input bias current of a BiFET amplifier but which offers a significantly lower IB drift over temperature. It utilizes super-beta bipolar input transistors to achieve picoampere input bias current levels (similar to FET input amplifiers at room temperature), while its IB typically only increases by 5× at 125°C (unlike a BiFET amp, for which IB doubles every 10°C resulting in a 1000× increase)
The AD704 quad operational amplifier offers picoampere input bias current, low offset voltage (75 µV max) and low noise (0.5 µV p‑p from 0.1 Hz to 10 Hz). It is available in several temperature‑grade versions (commercial, industrial and military) and in multiple package types such as 14‑lead DIP, SOIC and LCC.
Typical applications include low‑frequency active filters, precision instrumentation, ECG/EKG front‑ends and weigh‑scale circuits. The device is internally compensated for unity gain and can operate from a single supply of up to +18 V.
| Input Offset Voltage (typical) | 75 µV |
|---|---|
| Input Noise (0.1 Hz‑10 Hz) | 0.5 µV p‑p |
| Supply Current (per amplifier) | 600 µA max |
The typical offset voltage drift is 1 pV/°C.
The device can operate from a supply voltage of +2 V up to +18 V.