Study of Small-signal Model of Simple CMOS Amplifier with Instability Compensation of Positive Feedback Loop

Measurement Science Review

Lahiri A.¹  Dostal T.²  Sotner R.³  Vrba K.⁴  Herencsar N.⁴  Jerabek J.⁴ 

[1] D3-Friends Apartments, IP Extension, Delhi, India;Dept. of Electrical Engineering and Computer Science, College of Polytechnics Jihlava, Jihlava, Tolsteho 16, 586 01, Czech Republic;Dept. of Radio Electronics, Faculty of Electrical Engineering and Communication, Brno University of Technology, Technicka 3082/12, 61600, Brno, Czech Republic;Dept. of Telecommunications, Faculty of Electrical Engineering and Communication, Brno University of Technology, Technicka 3082/12, 61600, Brno, Czech Republic;

关键词: active elements;    instability compensation;    variable gain amplifier;    voltage buffer;    voltage follower;    voltage gain adjusting;   

DOI  :  10.1515/msr-2015-0021

来源: DOAJ

【 摘 要 】

The paper deals with precise analysis of simple AC variable gain CMOS amplifier. The circuit can be used as a simple voltage follower (6 MOS transistors are required) or amplifier. The main attention of this work is focused on a small-signal model of the proposed block and effects of additional passive network leading to compensation of its instability. The continuous gain adjusting in range from 1.1 to 10 (0.8 – 20 dB and with bandwidth 4.9 - 90 MHz at 5 pF load capacitance) is possible and the proposed amplifier is suitable for implementation in systems, where lower range of gain adjusting and large dynamical range is required. Theoretical analyses are supported by PSpice simulations (TSMC 0.18 um technological models) and experimental measurements with commercially available CMOS transistor fields (ALD1106/7) also confirm the discussed behavior of the amplifier.

【 授权许可】

Unknown