Title :
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
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;
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
DOI :
10.1109/CAR.2009.24
