Dr. Deepak Sekar

🎯 Post Title: "Gain vs Bandwidth — The Tug of War Every Analog Designer Plays" 📖 The Classic Struggle Meet Arjun, an analog designer, stuck between two friends who just can’t agree: Gagan Gain: loves amplifying everything Bala Bandwidth: loves speed and range The problem? Whenever Arjun makes Gagan stronger, Bala slows down. Whenever Bala speeds up, Gagan becomes weaker. Welcome to the Gain–Bandwidth Tradeoff — the fundamental rule that shapes almost every analog design decision. 🔍 What They Mean in Real Life Gain (Av): “How much bigger can I make the output compared to the input?” Think of it as volume boost in music. Bandwidth (BW): “How wide a range of frequencies can I handle effectively?” Think of it as how high the treble and how low the bass can go without distortion. In most amplifier designs, Av × BW ≈ constant (for a given technology). That means — you can’t have infinite gain and infinite bandwidth at the same time. 🏗 Applications & What They Need Sensor Front Ends: Need high gain but don’t care about very high bandwidth. High-Speed ADC Drivers: Need wide bandwidth even if gain is modest. RF Amplifiers: Bandwidth is fixed by the channel, but gain must be just enough to meet the link budget without adding noise. Precision Instrumentation: Prioritize gain accuracy over extreme bandwidth. ⚖ Why It’s Critical If you mess this up: Too much gain, low bandwidth → Signal will be clean but slow, missing fast changes. Too much bandwidth, low gain → You’ll pass everything, including noise, and won’t see small signals. Every design must balance based on what the application values most. 🛠 How to Judge the Right Balance 1. Know the Signal: What’s the highest frequency component you must pass without distortion? 2. Check the SNR Target: Higher gain can help small signals beat the noise floor. 3. Understand the Next Stage: Does your output drive an ADC? A mixer? A filter? That sets bandwidth needs. 4. Look at Technology Limits: fT, parasitics, and process variations will cap your gain–bandwidth product. 📋 Design Steps to Follow 1. Set Gain Requirement: From system specs, find the minimum gain to meet noise and amplitude targets. 2. Set Bandwidth Target: Based on signal spectrum and oversampling margins. 3. Pick Topology: Common-source, folded cascode, or differential op-amp — each has different gain–BW tradeoffs. 4. Bias for Balance: More bias current can push bandwidth higher but might limit achievable gain. 5. Use Compensation Wisely: Miller caps, lead-lag networks, and feed-forward paths can shape bandwidth without killing gain. 6. Simulate in Corners: Verify gain and bandwidth across process, voltage, and temperature (PVT). 💡 Final Thought > “Gain without bandwidth is like shouting slowly. Bandwidth without gain is like whispering very fast. The art of analog design is knowing when to shout and when to whisper.”

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Fourteen Indian faculty leaders from among the top Indian academic research institutions are offering first of- their- kind and most leading-edge ,next- gen  Design, Device, Packaging and System(IDSPS) tutorials in all strategic  semiconductor, packaging and systems areas to educate next gen graduate students and re-educate industry professionals from other sectors. This is historic and all  semiconductor and packaging companies  in India should send their engineers to take these courses. Similarly, all academic research institutions should send their new faculty and grad students. I'm very proud of the IDSPS faculty team for offering 14 state- of- the art professional courses at ISPEC conference at IITGN on March 4. 2025. In my previous post I listed all 14 courses and a website to register( ispec.co.in)  Here are the details of course number 1    Course  No.1   Next- Gen CMOS Semiconducrs : Status and Future Tutor : Prof. Nihar Ranjan Mohapatra, IIT Gandhinagar The evolution of CMOS technology has been the driving force behind the digital revolution, enabling exponential growth in computing power and energy efficiency. However, as the industry approaches the physical and economic limits of Moore's Law, the need for innovative approaches to overcome scaling- performance bottlenecks has never been more critical. This short course, is designed to provide a comprehensive overview of how CMOS technology has evolved, and the cutting-edge advances and emerging paradigms  that are shaping the future of the semiconductor industry. The course will begin by tracing the journey of CMOS evolution, from traditional planar MOSFETs to the introduction of FinFETs and Nanosheet FETs, which have redefined performance benchmarks. It will then explore the exciting potential of Complementary FETs (CFETs) and stacked CMOS technologies, which promise unprecedented transistor integration density and energy efficiency. Particular focus will be placed on Gate-All-Around (GAA) architectures, which are becoming critical for sub-3nm nodes, along with the advent of multi-patterning lithography techniques, including EUV lithography, and their role in pushing scaling limits. Participants will also be introduced to the role of power-performance-area-cost (PPAC) optimization, and how design-technology co-optimization (DTCO) is reshaping the industry. This course is designed for students, researchers, and professionals eager to stay at the forefront of semiconductor technology. By the end of this course, participants will have a  good understanding of the state-of-the-art in CMOS advancements, the strategic shifts required to address future challenges, and the exciting opportunities that lie ahead for the semiconductor industry. This knowledge will empower participants to learn and contribute meaningfully to the design, development, and application of future-generation semiconductor technologies, to contribute in an ever-evolving technological landscape.

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India consumes $100B+ in electronics every year. But we still don’t have a single globally recognised electronics brand. While China invested in innovation, we settled for import-friendly margins. This is the Decade of LOEMs—Local OEMs who own design, IP, and ambition. Here’s why this matters more than ever 👇 #LOEMs #manufacturing #semiconductors #makeinindia #BESEMI Atomberg Technologies DailyObjects Havells India Ltd IFB Appliances Voltas Limited - A TATA Enterprise Samsung Semiconductor Sony LG Electronics Nokia BigEndian Semiconductors

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