A low noise CMOS preamplifier for femtoampere current detection

Author

Zhang, Ming ; Llaser, Nicolas ; Mathias, Herve

Author_Institution

MiNaSys, Univ. of Paris XI, Orsay

fYear

2008

fDate

18-21 May 2008

Firstpage

2094

Lastpage

2097

Abstract

This paper presents a low noise CMOS preamplifier for femtoampere detection. Based on a classical charge amplifier, a ping-pong technique is proposed to reset the charge amplifier, keeping the preamplifier stable even in a strong parasitic DC current. With a low reset frequency, the undesired folding noise is greatly reduced and the signal-to-noise ratio (SNR) at the output can be kept almost constant. The simulation results show that using the proposed preamplifier, the output SNR can still be 72 for an input current of 200 fA among a parasitic DC current of 100 pA. The dynamic range is observed over 120 dB.

Keywords

CMOS integrated circuits; electric current measurement; integrated circuit noise; low noise amplifiers; charge amplifier; femtoampere current detection; input current; low noise CMOS preamplifier; parasitic DC current; ping-pong technique; signal-to-noise ratio; Current measurement; Dynamic range; Feedback; Low-frequency noise; Low-noise amplifiers; Noise reduction; Preamplifiers; Resonant frequency; Rotation measurement; Signal to noise ratio;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 2008. ISCAS 2008. IEEE International Symposium on

Conference_Location

Seattle, WA

Print_ISBN

978-1-4244-1683-7

Electronic_ISBN

978-1-4244-1684-4

Type

conf

DOI

10.1109/ISCAS.2008.4541862

Filename

4541862