The AC performance of an analog-to-digital converter depends on its architecture. In part 3 of this series, we discussed the integral nonlinearity (INL) error of an analog-to-digital converter (ADC), noting that gain, offset, and INL error all contribute to the total unadjusted error. This metric provides an overall view of an ADC’s DC performance. Q: What about the AC […]
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Understanding ADC specs and architectures: part 3
Integral nonlinearity tracks the cumulative effects of an ADC’s differential nonlinearity. In part 2 of this series, we discussed several sources of error in an analog-to-digital converter (ADC), including gain, offset, missing-code error, and differential nonlinearity (DNL). We concluded with an illustration of a waveform with varying levels of DNL superimposed on the staircase representing […]
Understanding ADC specs and architectures: part 2
Specifications such as gain error, offset error, and differential nonlinearity help define an analog-to-digital converter’s performance. In part 1 of this series, we discussed an ideal analog-to-digital converter (ADC), noting that it would have infinite resolution and bandwidth. Then we looked at the real world of practical inverters and how their resolution, expressed in a […]
Understanding ADC specs and architectures: part 1
Analog-to-digital converters are the heart of most test equipment, setting the stage for the digital processing of analog signals. Several posts over the past year or so have involved digital signal processing. For example, we have covered the fast Fourier transform (FFT), the inverse FFT, and discrete convolution. To perform these operations on real-world signals, […]
Review: Micsig TO3004 tablet oscilloscope
If you’re looking for a portable oscilloscope for field troubleshooting or for demonstrations, look at the Micsig TO series. Here’s my take on the four-channel 300 MHz variant, TO3004. The Micsig TO3004 oscilloscope (Figure 1) is an 8-bit, four-channel, tablet-sized portable oscilloscope that’s also available with 100 MHz and 200 MHz varieties with two or […]
How to use convolution to implement filters: part 4
A windowed sinc function can implement a low-pass filter, and a two-dimensional convolutional filter can blur or sharpen images. In part 3 of this series, we introduced a low-pass filter based on the Sinc function and described the need for windowing to compensate for sampling and truncation. Q: How can we apply this filter? A: […]
Why engineers need IC ESD and TLP data
Design Engineers need ESD and TLP characterization data to make informed decisions to design robust circuits and systems. Engineers often review semiconductor data among several manufacturers when designing a circuit or system. While two or more ICs may perform satisfactorily under normal operating conditions, they may not perform the same under extreme conditions, such as […]
What is bit jitter, and what are its component jitters?
Bit jitter can be a problem. A digital data stream is composed of a series of rapidly changing “ones” and “zeros.” Bit jitter can make it difficult to tell the difference and result in data errors. This article begins by defining jitter, then looks at its component jitters, compares bit jitter with clock jitter, considers […]
How to calculate and apply the inverse discrete Fourier transform: part 4
In part 3 of this series, we used the inverse fast Fourier transform (IFFT) to create 100-Hz time-domain waveforms of various amplitudes and phases. We can also use the IFFT to create waveforms containing multiple frequencies. If you look closely at Figure 1 in part 1 of this series, you’ll notice that the time-domain waveform […]
How to calculate and apply the inverse discrete Fourier transform: part 3
The inverse transform can create a time-domain waveform where no waveform has been before. In part 2 of this series, we used the discrete Fourier transform to convert a waveform from the time domain to the frequency domain, operated on the frequency-domain data, and used the inverse transform to reconstruct the altered time-domain waveform. That’s […]
