Category Archives: Data Converter

Getting Started With Delta-Sigma ADC Design

ADC is an irresistible topic for a Nyquist ADC designer. Several years ago I touched a bit of it when I studied noise-shaping SAR ADC. Recently I have the opportunity to revisit this topic. The good thing is that there … Continue reading

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Pulse Generator of Asynchronous SAR ADC

When it comes to designing SAR ADC, I am like a tortoise and can never imagine the world of rabbits. Recently I got some time to ponder how the rabbits can run so fast. One of the critical factors is … Continue reading

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Memos on FFT With Windowing

Coherent sampling is quite difficult to meet under the lab conditions. One has to go for windowing to characterize the dynamic performance of ADC. Though seminal papers and reports [1-2] lie on my desk for quite long time, I still feel … Continue reading

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Brief Study of Noise-Shaping SAR ADC – Part C

The topic of noise-shaping SAR ADC will come to an end in this post. In Part A, I briefly talked about the concept of noise shaping applied to sigma-delta modulators. In Part B, I introduced one special property of SAR … Continue reading

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Brief Study of Noise-Shaping SAR ADC – Part B

In the previous post, I’ve shared some basics of sigma-delta ADC. In this post, before we look at the noise-shaping SAR ADC, let’s again do a warm-up. The z-domain linear model for a 1st-order sigma-delta modulator: The linear model has … Continue reading

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Brief Study of Noise-Shaping SAR ADC – Part A

Sometimes it is much easier to become a fan of something when you only know something about it. Just like Sigma-Delta ADC, it is so complicated that even though I have learned it for several times I still can’t fully understand it! Nevertheless, I am … Continue reading

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Noise Effect On The Distribution of ADC Output Codes

In the previous post, the probability of comparator decision with the existence of noise was calculated. In this post, the topic about noise and probability will continue. The whole topic is actually inspired by a 1986-paper [1], which discusses noise effect … Continue reading

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Brief Study of Dither C: Dithered DNL

In ‘Dither’ series B, I have shown dither reduces the harmonic distortion by decolalizing the code mapping of the analog signal from the transfer curve. So if we take a step further, we might say the main purpose of dither is … Continue reading

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Brief Study of Dither B: Dither

In ‘Dither’ series A, I mentioned that the quantization will introduce large harmonics to a low-level sinusoidal signal. Let’s look at another example in Figure 1 [1]. Adding dither to the circuit means adding noise to the circuit. Now let’s … Continue reading

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Brief Study of Dither A: Before Dither

Does it make sense to add noise to enhance the converter’s performance? Dither – a puzzle to me for quite a long time. Recently I had time to read several related papers and APs. I would like to share some … Continue reading

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