The AD549JHZ is a monolithic electrometer Operational Amplifier with very low input bias current. Input offset voltage and input offset voltage drift are laser trimmed for precision performance. The ultralow input current of the part is achieved with Topgate™ JFET technology, a process development exclusive to Analog Devices, Inc. This technology allows fabrication of extremely low input current JFETs compatible with a standard junction isolated bipolar process. The 10¹⁵R common-mode impedance, which results from the bootstrapped input stage, ensures that the input current is essentially independent of the common-mode voltage. The AD549 is suited for applications requiring very low input current and low input offset voltage. It excels as a preamp for a wide variety of current output transducers, such as photodiodes, photomultiplier tubes or oxygen sensors.
Input bias current guaranteed over the common-mode
