%0 Journal Article
%T A Linear CMOS OTA and Its Application to a 3. 3V 20MHz High-Q gm-C Bandpass Filter<br>A Linear CMOS OTA and Its Application to a 3.3V 20MHz High-Q gm-C Bandpass Filter
%A Wang Bin
%A Yang Huazhong
%A <br>Wang
%A Bin
%A an
%A Yang
%A Huazhong
%J 半导体学报
%D 2005
%I 
%X A design of a linear and fully-balanced operational transconductance amplifier (OTA) with improved high DC gain and wide bandwidth is presented.Derivative from a single common-source field effect transistor (FET) cascade and its DC I-V characteristics,the third-order coefficient g3 has been well compensated with a parallel FET operated in the triode region,which has even-odd symmetries between the boundary of the saturation and triode region.Therefore,for high linearity,a simple solution is obtained to increase input signal amplitude in saturation for the application of OTA continuous-time filters.A negative resistance load (NRL) technique is used for the compensation of parasitic output resistance and an achievement of a high DC-gain of the OTA circuits without extra internal nodes.Additionally,derivations from the ideal -90. phase of the gm-C integrator mainly due to a finite DC gain and parasitic poles will be avoided in the frequency range of interest.HSPICE simulation shows that the total harmonic distortion at 1Vp-p is less than 1% from a single 3.3V supply.As an application of the VHF CMOS OTA,a second-order OTA-C bandpass filter is fabricated using a 0.18μm CMOS process with two kinds of gate-oxide layers,which has achieved a center frequency of 20MHz,a 3dB-bandwidth of 180kHz,and a quality factor of 110.
%K linear OTA
%K high DC-gain
%K high Q
%K bandpass filter<br>linear
%K OTA
%K high
%K DC-gain
%K high
%K Q
%K bandpass
%K filter
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=5B3AB970F71A803DEACDC0559115BFCF0A068CD97DD29835&cid=1319827C0C74AAE8D654BEA21B7F54D3&jid=025C8057C4D37C4BA0041DC7DE7C758F&aid=D5A7FD29B7466588&yid=2DD7160C83D0ACED&vid=96C778EE049EE47D&iid=F3090AE9B60B7ED1&sid=22AA0D3D54DBF917&eid=BCA72E9D2CFA70A9&journal_id=1674-4926&journal_name=半导体学报&referenced_num=0&reference_num=16