A Novel Digital Lock-in Amplifier with Dual Channels

Author

Wu, Dongyue ; Wang, Chao ; Sun, Hongjun ; Wang, Huaxiang

Author_Institution

Sch. of Electr. Eng. & Autom., Tianjin Univ., Tianjin

fYear

2009

fDate

1-2 Feb. 2009

Firstpage

464

Lastpage

468

Abstract

In order to sample two channels mixing frequency signals in high speed and process them synchronously in the system, a dual-channel, high-speed digital lock-in amplifier (LIA) that uses orthogonal digital demodulation is proposed. The instrument, based on a digital signal processor (DSP) and its associated hardware, is implemented. The system adopts a method of high speed bi-directional parallel communication between DSP and parallel interface of PC by EPP (Enhanced Parallel Port) protocol. The EPP achieves an easy installation for industrial applications. The experimental tests showed that the system is feasible.

Keywords

amplifiers; demodulation; digital signal processing chips; protocols; signal sampling; telecommunication channels; bi-directional parallel communication; digital lock-in amplifier; digital signal processor; dual channel; enhanced parallel port protocol; frequency signal; maximum sampling frequency; orthogonal digital demodulation; parallel interface; Amplifiers; Bidirectional control; Demodulation; Digital signal processing; Digital signal processors; Frequency; Hardware; Instruments; Protocols; Signal processing; Digital lock-in amplifier; mixing frequency; orthogonal digital demodulation; port dual channels;

fLanguage

English

Publisher

ieee

Conference_Titel

Informatics in Control, Automation and Robotics, 2009. CAR '09. International Asia Conference on

Conference_Location

Bangkok

Print_ISBN

978-1-4244-3331-5

Type

conf

DOI

10.1109/CAR.2009.24

Filename

4777281