Interview Question

Mixed Signal Test Bench Engineer ( Mainly ADC) Interview San Diego, CA

Its an ADC Testing Day - Every interview was like go in to

  the room , they asked me to go to the board , and started questioning. But it was nice experience , it was question to answer interviews. 1)Draw Frequency Spectrum of output of an ADC , when the ADC is undersampled . Say f(in) = 10 MHz and Fs= 7 MHz. 2)Square wave in frequency domain will have odd or even harmonics ? 3) Every interviewer asked about how to test the static and dymanic parameters of an ADC, like DNL,SNDR, SNR (ideal). , Histogram Techniques , Coherent Sampling , Windowing, Ramp input vs Sine wave input testing 4)Basics on dB,dBm andfind rms power output. Given an input signal. 5)RC filter output wave amp and phase vs freq plots., transfer function of high pass filter 6)Some C programming questions. - String reversal, sorting, find max number, find prime number. 7)Some questions based on resume. ( projects ,very few) 8)Testing a DAC 9)Transmission Line - Impedence matching questions. Director asked me one question on how would I like to see myself in 5 years from now.

Interview Answer

2 Answers


Answer for question 1 - We hav an alias at 3 MHz (fin - fs) and fundamental signal power(Vin/(1.414) at 10 MHz.

Interview Candidate on Jan 7, 2013

Square wave in frequency domain will have odd or even harmonics ?
odd, as 3f, 5f,7f (f is the frequency of the square wave)

newsan on Mar 8, 2013

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