AUTOMATED AMPLIFIER FREQUENCY RESPONSE TESTER

ARPITA AWALEGAONKAR, VIVEKANAND EDUCATION SOCIETY INSTITUTE OF TECHNOLOGY

AD9850 signal generator module, Arduino UNO interfacing with MATLAB, Bode plot, DDS(Direct Digital Synthesis), MATLAB GUI, Programmable frequency generation

With current developments in Integrated circuit technology, an approach to automatically plot the frequency response of different Audio amplifier circuits is presented in this paper. Use of specialized IC named Direct Digital Synthesizer (DDS) in programmable generation of frequency/ phase tunable output signal based on a reference clock source is incorporated. Interfacing of DDS with a microcontroller based Arduino board provides the basis of frequency generation in this project. This output from DDS is fed to test Audio amplifier circuit and the response from amplifier is recorded, voltage gain is calculated and a plot of gain versus frequency is displayed on PC by means of MATLAB graphic user interface (GUI). The aim is to replace the costlier and rigid option of Data acquisition (DAQ) card for the acquisition and display of frequency response plot on PC with microcontroller based Arduino board interfaced with MATLAB. This approach is cost effective, portable and unconstrained.
    [1] Walt Kester, “MT-085: Fundamentals of Direct Digital Synthesis (DDS)”, Analog Devices, Year, page. 1-4. [2] Eva Murphy and Colm Slattery “Ask The Application Engineer—33 All About Direct Digital Synthesis “, Analog Dialogue 38-08, August (2004 ). [3] “A Technical tutorial on Digital Signal Synthesis”, Analog Devices Inc. ,1999 [4] Jouko Vankka,” Direct Digital Synthesizers: Theory, Design and Applications”, Journal no.9512253186, November(2000) [5] Shuying Qi, Foster Dai, Charles Stroud, and Dayu Yang “Analog Circuit Testing Using Built-In Direct-Digital Synthesis” [6] Jim Surber and Leo McHugh “Single-Chip Direct Digital Synthesis vs. the Analog PLL”, Analog Dialogue 30-3 (1996), pg-12-13 [7] “AD9850 Datasheet”, Analog Devices
Paper ID: GRDJEV01I070085
Published in: Volume : 1, Issue : 7
Publication Date: 2016-07-01
Page(s): 108 - 111