Author Archives: Dai

100 Keywords – Holes

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

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

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

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

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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Leading Simulators for Analog/RF Circuits

Recently I have the opportunity to touch some RF design. WoW, some simple metal lines need a fancy tool to get them modeled! WoW, both Windows and Unix tools are involved to simulate the EVM! It seems that Cadence Spectre … 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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Ringing in Step Response

Is it possible to tell the stability of a negative-feedback circuit by just looking at its step response? The answer is yes. In this post, I will try to find the relationship between phase margin and ringing in step response. I … 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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Capacitor as a Discrete-Time Resistor

Prof. Ali has a column called “Circuit Intuitions” in the IEEE Solid-State Circuits Magazine. This time he wrote about capacitor as a resistor, which is quite helpful for me to understand this property recognized by James Clerk Maxwell 140 years … Continue reading

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