The hottest Circuits Substack posts right now

And their main takeaways
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It's hard to build an oscillator

lcamtuf’s thing • 7958 implied HN points • 21 Nov 25
đź•ą Technology Circuits
  1. Building a reliable oscillator is tough because it needs gain to work. Without gain, any oscillation will die out quickly.
  2. Using a Schmitt trigger can help create an oscillator with no stable midpoint. This means the circuit will keep switching back and forth, creating consistent oscillations.
  3. Different methods exist to build oscillators, like using op-amps or creating resonance with phase shifts. Each has its own way of generating oscillation, but they all need a careful balance of components.

Cursed circuits: charge pump voltage halver

lcamtuf’s thing • 4693 implied HN points • 02 Dec 25
đź•ą Technology Circuits
  1. Charge pumps are efficient circuits that can double voltage using capacitors. They work by transferring charge between capacitors to create a higher voltage output.
  2. Unlike standard voltage dividers, a specific charge pump design can halve voltage. This is done by using capacitors in series and moving a 'flying' capacitor to balance the voltages.
  3. The charge transfer stabilizes the output voltage at half the supply, which is different from typical voltage dividers since it doesn't depend on the size of the capacitors.

Resistors are out to get ya

lcamtuf’s thing • 2652 implied HN points • 28 Nov 23
🔬 Science Circuits
  1. Some components in electronics, like resistors, may not behave exactly as expected especially at high frequencies.
  2. Parasitic impedance and capacitance in resistors can affect circuit performance, especially in applications like feedback loops for operational amplifiers.
  3. Using a two-stage amplifier can help mitigate issues caused by resistor parasitics and ensure better signal integrity.

Energy in electronic circuits

lcamtuf’s thing • 2244 implied HN points • 16 Oct 23
🔬 Science Circuits
  1. Designing electronic circuits has become more stringent over the years due to advancements in technology.
  2. Understanding how energy travels through electronic circuits is crucial for circuit stability and efficiency.
  3. High-speed signals in electronic circuits can lead to significant energy expenditure and signal integrity issues.

Signal Integrity fundamentals

Only Wonder Knows • 117 implied HN points • 09 Jun 23
đź•ą Technology Circuits
  1. High speed digital design is not black magic, but engineering magic.
  2. In high speed designs, the generator sees only the cable, not the load, to determine current.
  3. Proper termination with load impedance equal to cable characteristic impedance prevents signal reflection.
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Fuses

Only Wonder Knows • 39 implied HN points • 17 Nov 23
đź•ą Technology Circuits
  1. Fuses are essential components for providing protection in electronic circuits by blowing up when the current exceeds a certain threshold.
  2. Fuses have specific ratings like amperage and voltage, and their behavior can be affected by factors like temperature and pulse energy.
  3. Understanding the details of fuses is crucial for designing reliable circuit boards and ensuring proper functionality.

Signal reflections in electronic circuits

lcamtuf’s thing • 185 HN points • 25 Nov 23
đź•ą Technology Circuits
  1. Signal reflections in electronic circuits can cause echoes of previously-transmitted signals due to impedance discontinuities.
  2. Electronic signals do not propagate through wires instantly, but travel at high speeds, around 80% of the speed of light in vacuum.
  3. Matching the characteristic impedance of the transmission line to the transmitter helps avoid issues with signal reflections in high-speed digital electronics.

Chopper amplifiers: history and present

Only Wonder Knows • 19 implied HN points • 15 Dec 23
🔬 Science Circuits
  1. Chopper amplifiers are a technique to reduce DC offset and low frequency noise in amplifiers.
  2. Historically, chopper amplifiers have been implemented using innovative methods like optical chopping with cadmium sulfide light-dependent resistors.
  3. Contemporary engineers can refer to Jim Williams' design for an ultrahigh performance instrumentation amplifier that resembles the old chopper amplifier concept.

Offline Microcontroller Simulator

Barn Lab • 0 implied HN points • 18 Feb 23
đź•ą Technology Circuits
  1. SimulIDE is a real-time electronic circuit simulator for hobbyists and students.
  2. The simulator requires the installation of Arduino IDE and libraries for custom functions.
  3. SimulIDE's UI can be clunky, but it offers real-time monitor features for checking register contents.