Title :
A 50-fA junction-isolated operational amplifier
Author :
Close, Joann P. ; Counts, Lewis W.
Author_Institution :
Analog Devices, Wilmington, MA, USA
fDate :
6/1/1988 12:00:00 AM
Abstract :
A monolithic op amp with 50-fA input current, 0.25-mV offset voltage, and 5- mu m V/ degrees C offset drift has been fabricated on a linear bipolar junction-isolated process. The low input current is achieved by using a pair of low-leakage four-terminal JFETs as input devices. Drift and offset voltage are adjusted by laser trimming on-chip thin-film resistors. The input JFET and the design of the amplifier are discussed.<>
Keywords :
bipolar integrated circuits; instrumentation amplifiers; linear integrated circuits; operational amplifiers; 0.25 mV; 50 fA; differential input; drift voltage adjustment; electrometer amplifier; four-terminal JFETs; linear IC; linear bipolar junction-isolated process; low input current; low-leakage; monolithic op amp; offset voltage; operational amplifier; Diodes; Implants; Low voltage; MOSFET circuits; Noise level; Operational amplifiers; Photodiodes; Probes; Protection; Transistors;
Journal_Title :
Solid-State Circuits, IEEE Journal of
