AD549

Data Sheet FEATURES Ultralow input bias current 60 fA maximum (AD549L) 100 fA maximum (AD549K) 250 fA maximum (AD549J) Input bias current guaranteed over the common-mode voltage range Low offset voltage 0.50 mV maximum (AD549K) 1.00 mV maximum (AD549J) Low offset drift 15 μV/°C maximum (AD549K) 20 μV/°C maximum (AD549J) Low power 700 μA maximum supply current Low input voltage noise 4 μV (typ) p-p over 0.1 Hz to 10 Hz MIL-STD-883B parts available APPLICATIONS Electrometer amplifier Photodiode preamp pH electrode buffer GENERAL DESCRIPTION The AD549 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...