AD706ARZ

The AD706ARZ is a picoampere input current dual bipolar Operational Amplifier that has the low input bias current of a JFET amplifier, but which offers a significantly lower IB drift over temperature. It utilizes superbeta 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 5x at 125°C (unlike a JFET amp, for which IB doubles every 10°C for a 1000x increase at 125°C). The AD706 also achieves the microvolt offset voltage and low noise characteristics of a precision bipolar input amplifier. Since it has <200pA of bias current, the AD706 does not require the commonly used balancing resistor. Furthermore, the current noise is only 50fA/?Hz, which makes this amplifier usable with very high source impedances. At 600µA maximum supply current (per amplifier), the AD706 is well suited for today's high density boards.