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Зустріч між новим головою Наглядової Ради і керівництвом КПІ ім. Ігоря Сікорського kpi пн, 06/09/2025 - 19:09

Editor’s Note: This DI is a two-part series.

In Part 1, Nick Cornford deliberately oscillates the TDA7052A audio power amplifier to produce a siren-like sound and, given the device’s distortion characteristics, a functional Wien bridge oscillator.

In Part 2, Cornford minimizes this distortion and adds amplitude control to the circuit.

In the first part of this Design Idea (DI), we saw how to use the TDA7052A (or similar) power amp to build a minimalist siren-type power oscillator, and also, having looked at that device’s distortion characteristics under various operating conditions, a simple but half-decent Wien bridge oscillator. In this second part, we’ll turn that semi-decency into something even more respectable, concentrating on minimizing distortion and ignoring the siren song of raw power. We will also stick with a 5-V supply, even though the chip can handle up to 18 V. Figure 1 shows the new circuit.

Figure 1 Adding more precise level-sensing allows much better amplitude control and also reduces distortion.

Most of the changes are in the control loop, but input resistor R5 has been increased because we have more gain available now that Vcon can be driven high as well as just being pulled low. In passing, the series combination of R5 and U1’s nominally 20k input resistance shunts R2/R4 a little; a slightly disturbing operation. Adding 120k across R1/R3 could compensate for that, but the practical difference is tiny. The gangs on twin pots never quite match anyway, so using the lower-value half for R1 is good enough.

Wow the engineering world with your unique design: Design Ideas Submission Guide

The control loop, detailed

Peak output levels are now sensed by comparison with the reference voltage defined by R9 (or its wiper) and R10. (Be careful: pot R9 and fixed resistor R10 should match, so the latter may need to be trimmed.) The junction of R11 and R12 floats at ~650 mV until the peak amplitude exceeds the reference, when D1 or D2 will briefly pull it lower by ~450 mV. The resulting attenuated pulse stream is filtered by R6/C6 and R7/C7 and level-shifted and buffered by Q1 into U1’s Vcon pin. That attenuation is necessary because the effective control-loop gain would otherwise be excessive. U2 is an MCP6022, which has a low input-offset voltage and is fast enough to work well as a comparator. The overall temperature stability is good, the output level scarcely changing between 20°C and ~50°C.

Any residual ripple in a control loop like this will cause distortion by modulating the signal. It’s minimized by the lead-lag filter R6/C6 and C7/R7, which also controls the settling time. The values used leave the loop somewhat under-damped at low frequencies, but are a good compromise.

The spectra with unloaded outputs at 0 dBV and -10 dBV are both shown in Figure 2.

Figure 2 The spectra for 1 kHz outputs at 0 dBV and -10 dBV, showing THDs of around -60 and -73 dB respectively—say 0.1% and 0.02%.

Further reducing the output levels doesn’t improve distortion much, partly because this control scheme then becomes less stable. Any offset of one output relative to the other can result in one “phase” of pulses being missed, leading to increased second-harmonic distortion, as implied by the relative levels of second and third harmonics for the two levels shown in Figure 2. Trimming the power amp’s offset makes surprisingly little difference, so it isn’t implemented.

Trying to derive the control voltage from a more complex full-wave rectifier gave virtually the same distortion figures, so we’ll stick to Figure 1’s circuit, run it at -10 dBV or a little less, and accept its THD.

 Some finishing touches

Swapping the capacitors C1 and C2 for 3n3 and 330n parts gave the expected performance on higher and lower ranges, though distortion was a few dB higher on the low range, and the level was less well-controlled at the highest frequencies. All that’s needed to turn this into a useful kit is an output stage, for which the fairly conventional circuit of Figure 3 works well.

Figure 3 A simple output stage can deliver up to about +5 dBV, which is the rail-to-rail swing for a 5 V supply.

The extra stage adds almost no distortion, and leaves a spare op-amp (U3b) which could be used to invert the signal from U3a to provide antiphase outputs. One final spectrum, taken with the oscillator set for -10 dBV and the output for a swing of nearly 5 V, is in Figure 4. That confirms an overall THD of -73 dB, or 0.022%. Hardly earth-shattering, but still quite decent.

Figure 4 The spectrum at the output of Figure 3 for an output of ~+5 dBV.

No tweeters were harmed in the making of this DI, though a 10-Ω, 1/4-W load resistor started to smoke. A 1-W part would have been healthier, as it would only have vaped.

—Nick Cornford built his first crystal set at 10, and since then has designed professional audio equipment, many datacomm products, and technical security kit. He has at last retired. Mostly. Sort of.

Related Content

• Power amplifiers that oscillate—deliberately. Part 1: A simple start.
• Ultra-low distortion oscillator, part 1: how not to do it.
• Ultra-low distortion oscillator, part 2: the real deal
• Distortion in power amplifiers, Part IV: the power amplifier stages
• A pitch-linear VCO, part 1: Getting it going
• A pitch-linear VCO, part 2: taking it further

The post Power amplifiers that oscillate—deliberately. Part 2: A crafty conclusion. appeared first on EDN.

Qualcomm’s $2.4 billion acquisition of Alphawave Semi is expected to take the San Diego, California-based semiconductor powerhouse beyond mobile processors and into the world of AI and data center chips. Here is a closer look at how Alphawave’s SerDes and chiplet technologies could aid Qualcomm in making a foray into the booming markets for AI and data centers.

Read the full story at EDN’s sister publication, EE Times.

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• IP players prominent in chiplet’s 2024 diary
• Alphawave Semi’s quest for open chiplet ecosystem
• BoW Strengthens Pathway to Chiplet Standardization
• How the Worlds of Chiplets and Packaging Intertwine
• Why UCIe is Key to Connectivity for Next-Gen AI Chiplets

The post What does Qualcomm’s Alphawave acquisition stand for? appeared first on EDN.

На війні загинув випускник КПІ Данило Шляхов kpi пн, 06/09/2025 - 17:22

Результати проведення конференції "Бізнес, інновації, менеджмент: проблеми та перспективи" kpi пн, 06/09/2025 - 16:20

Anritsu Company will exhibit cutting-edge high-speed signal integrity solutions at the PCI-SIG Developers Conference from June 11-12 in Santa Clara, CA. Anritsu will present PCI-Express  6.0 and 7.0 live demonstrations of the industry-leading MP1900A BERT in collaboration with Synopsys, Teledyne LeCroy, CIG, and Tektronix.

Live Demonstrations

World’s First PCI-Express 6.0 Link Training over Optics

Anritsu is joining forces with Synopsys, Tektronix, and CIG to demonstrate the world’s first PCIe 6.0 optical connection link training using the Anritsu MP1900A BERT, Synopsys PCIe 6.x PHY and Controller IP, Tektronix DPO70000 Real Time Oscilloscope, and CIG OSFP LPO optical module.

PCIe over optical links provides higher bandwidth, covers longer distances, and is more energy-efficient, effectively addressing key bottlenecks for AI workloads in data centers.

This joint demonstration highlights Anritsu’s leadership in next-generation optical PCIe.

PCI-Express 7.0 Differential Skew Evaluation

In collaboration with Teledyne LeCroy, Anritsu will present a solution for evaluating the effect of differential skew in PCIe 7.0.

PCIe 7.0 uses PAM4 signaling, which reduces eye height by more than three times compared to NRZ. Combined with the speed increase from 32.0 Gbaud in PCIe 6.0 to 64.0 Gbaud, this results in a smaller unit interval (UI) that is significantly more sensitive to skew.

In high-speed environments, signals traversing an ISI channel may exhibit a dip in the fundamental frequency due to skew. While most BERTs lack built-in skew evaluation functions, Anritsu addresses this by using two MP1900A MU196020A PAM4 PPG units with the Channel Sync function to inject P-N skew and Teledyne LeCroy’s WaveMaster 8650HD 65 GHz oscilloscope for advanced analysis.

The post Anritsu to Showcase Groundbreaking PCI-Express 6.0 and 7.0 Demonstrations at PCI-SIG Developers Conference 2025 appeared first on ELE Times.

КПІ впроваджує підхід "compliance + values" задля формування сталої культури доброчесності kpi пн, 06/09/2025 - 11:59

Dowa Electronic Materials Co Ltd of Tokyo, Japan (a subsidiary of Dowa Holdings Co Ltd) has launched a surface-mountable device (SMD) in the peak wavelength range of 1040–1900nm made with its high-efficiency SWIR (short-wavelength infrared) LEDs. DOWA aims to expand business in the rapidly growing machine vision and healthcare markets...

Nanoelectronics research center imec of Leuven, Belgium and two imec research groups at Ghent University (the Photonics Research Group and IDlab) have demonstrated a fully integrated single-chip microwave photonics system, combining optical and microwave signal processing on a single silicon chip (Hong Deng et al, ‘Single-chip silicon photonic engine for analog optical and microwave signals processing’ Nature Communications volume 16, Article number 5087 (2025)). The chip integrates high-speed modulators, optical filters, photodetectors and transfer-printed lasers, making it a compact, self-contained and programmable solution for high-frequency signal processing. This can replace bulky and power-hungry components, enabling faster wireless networks, low-cost microwave sensing, and scalable deployment in applications like 5G/6G, satellite communications, and radar systems...

Silicon Valley-based tech incubator Plug and Play, which launched its semiconductors program in 2023, has joined hands with Synopsys to provide selected startups with access to its design tools and software licenses. The tie-up aims to lower the barrier to next-generation chip design, accelerate time to market, and reduce development costs across various chip-design stages.

Professional-grade EDA tools often represent a significant investment at the early stage, so this partnership will lower the barrier to entry for cutting-edge chip design. “This collaboration with Synopsys brings their trusted and comprehensive chip design software and solutions directly to the startups we support,” said Rouzbeh Borhani, head of Plug and Play Semiconductors.

The partnership also marks a significant move by Synopsys to win over chip startups while helping them innovate at the earliest stages of chip development. Moreover, Plug and Play can provide Synopsys access to deep tech firms beyond semiconductor startups.

Plug and Play has recently welcomed over 150 startups in its first Silicon Valley batch of 2025. These upstarts will gain hands-on support from industry experts, investors, and corporate partners in a 3-month program, which includes mentor-led workshops, private deal-flow sessions, and curated introductions designed to accelerate their business growth.

The program will also allow startups to secure pilots, proofs of concept, and potential investment without equity requirements. In this batch, 13% of startups are based in Silicon Valley, while 61% are from other parts of the United States. The remaining 26% of startups come from Canada, the United Kingdom, Hong Kong, and several other countries.

Related Content

• Silicon 100: Startups Worth Watching in 2024
• In search of new chip startup funding models
• 10 Chip Startups for AI in Edge and Endpoint Applications
• Startups eye opportunities amid analog industry consolidation
• Inference Sensing and In-Memory Computing Chip Startup Claims 20 TOPS/W

The post Tech incubator leasing EDA tools for chip startups appeared first on EDN.

Scratched that itch!! submitted by /u/Separate-Choice [link] [comments]

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I ordered this Mechanic LS720+ Polarization Ring Light for my work place. I just tested it at home lab with a stereo microscope. Now I have to buy my own :) It removes reflections really well. The images are not sharp because I held the light with my left hand and took photos with a smartphone through the microscope eye piece with my right hand. submitted by /u/1c3d1v3r [link] [comments]

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submitted by /u/ElectronSurf [link] [comments]

This is my first macropad, and I’ve built a custom microcontroller board based on the RP2040 (a copy of the Raspberry Pi Pico). Before I send it for manufacturing, I’d really appreciate it if someone could review it and suggest any improvements. I’m a bit nervous since it’s my first design. submitted by /u/NICKSIDD [link] [comments]

Зібрання документів професора І.Д. Жукова kpi пт, 06/06/2025 - 23:44

Кубок Нескорених з футболу в КПІ ім. Ігоря Сікорського kpi пт, 06/06/2025 - 23:39

Візит Посла Ізраїлю до КПІ ім. Ігоря Сікорського kpi пт, 06/06/2025 - 23:33

Just Refurbished one of this that still has an atmega (old > 6 years). New screen, new socket, bigger battery. :) submitted by /u/titojff [link] [comments]