公开(公告)号：US20020084851A1

公开(公告)日：2002-07-04

申请号：US09751981

申请日：2000-12-29

Applicant: SILICON INTEGRATED SYSTEMS CORP.

Inventor： Hung-Chih Liu ,  Stanley Liao

IPC: H03F003/45

CPC classification number: H03F3/45659 ,  H03F3/45273

Abstract: The present invention discloses a current feedback operational amplifier, whose input ends are connected to a first amplifier which transmits an output to the gate terminals of at least one input pair of current switches, and the source terminal of one transistor of the input pair of current switches is connected to one of the input ends. Therefore, a negative feedback loop will be established by the first amplifier and the input pair of current switches. By means of the negative feedback loop, the input impedance, offset voltage and gain error are all reduced. The input impedance of the present invention is reduced as 1/1nullA times as the original one. Therefore, the aspect ratio of the transistors of the input pair of current switches is reduced.