Author Archives: Dai

Getting Started With Delta-Sigma ADC Design

Posted on June 2, 2022 by Dai

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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My Circle is Like a Smith Chart

Posted on February 20, 2021 by Dai

Smith chart is used be mysterious to me. My daughter has an interesting book named my heart is like a zoo. This makes me come up with the story – my circle is like a Smith chart. I can find … Continue reading →

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Current-Mode-Logic (CML) Latch

Posted on January 5, 2021 by Dai

It’s a rather old topic and one can find many good references. In this post, I will write down some of my basic understandings on this circuit. Operation of CML latch Figure 1 shows a simplified block diagram of divider-by-2 … Continue reading →

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[M scripts] Speed estimation of CML latch

Posted on January 5, 2021 by Dai

The Matlab script used in this post:

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100 Keywords – Doping

Posted on December 13, 2020 by Dai

Doping is a technique used to modify the density of charge carriers in semiconductors. A small section of the periodic table is copied as follows. Boron is a “Group 3” element. It has 3 valence electrons in its outmost shell. … Continue reading →

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100 Keywords – Holes

Posted on November 28, 2020 by Dai

In reality, there are no holes! It just refers to positive charge. The diagram below shows positive charge travels from the left to the right of silicon. At t1, one electron is released which produces a positive charge (indicated as … Continue reading →

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100 Keywords – Silicon

Posted on November 27, 2020 by Dai

A silicon atom has 14 electrons. In its outmost shell, it has 4 valence electrons. Covalent bonding in silicon: Its resistivity drops as temperature rises. Density of free electrons in silicon can be calculated as: At T=300K,  In the same … Continue reading →

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100 Keywords – Preface

Posted on November 27, 2020 by Dai

Feng Tang once said that if you want to know a bit about a new field, go and find 100 keywords. Digest them in two or three days, and you will look like a professional. Somewhat make sense! This triggers … Continue reading →

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CMOS Single Stage

Posted on September 17, 2020 by Dai

Found an old drawing on CMOS single stage from many years ago.  Stay healthy!

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Basics On Active-RC Low-Pass Filters

Posted on February 19, 2020 by Dai

Just some basic understandings on analog filters which is inspired by ‘The Guru’ in our company. To clarify my thoughts, I will write in the format of Q&A. There are four questions to answer: What do we dream for a … Continue reading →

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