4 ms·

I suspect a lot of the hype comes from people who have never tinkered with electronics. Noise is always a problem. Just trying to measure a small signal is a p

I suspect a lot of the hype comes from people who have never tinkered with electronics. Noise is always a problem. Just trying to measure a small signal is a problem since your instruments (which are not perfect) can influence the circuit. Component tolerances are also a problem - if you're trying to do something super precise, you'll have to spend extra money on better components, which is why measurement instruments such as oscilloscopes are so expensive. In some ways the hardware fights against you in analog design. Digital just brushes that away by clamping all possible values to just two.

dragontamer 2y ago
Precise analog designs are tuned with provable error bounds. Actually, a digital potentiometer is likely used today to tune extremely tight tolerances. So a bit of digital technique but overall it's analog (since digital pots are just turning analog resistors on/off with switches) You buy 5% accurate components everywhere then just trim the errors down to 0.01%. Not easy per se, but 99.99% accuracy is doable at the student level with the right designs. Professional level precision analog designs are the 7+ digit multimeters (99.99999% accuracy). Yes, built out of just 1% accurate parts. If you need matching pairs, they make specially matched resistor chips or whatever. -------- The concepts aren't hard btw though maybe slightly out of date. The book Art of Electronics analyzes a 7+ digit accurate multimeter design from Agilent or something. Instead of using an analog pot to tune, today you'd use a digital pot. Otherwise, I'm pretty sure the overall analysis and technique holds in today's electronics market.
- lbourdages 2y ago
  Interesting. Would that be doable at a VLSI scale? I imagine that for large scale analog computers (like, neural networks) all these trimpots would become a challenge...
  - dragontamer 2y ago
    True. VLSI does have techniques though. A clocked capacitor can sorta-kinda act as a trimpot if you calibrate the clock for example. And capacitors and clocks are more amicable to VLSI.

dragontamer 2y ago

Precise analog designs are tuned with provable error bounds. Actually, a digital potentiometer is likely used today to tune extremely tight tolerances. So a bit of digital technique but overall it's analog (since digital pots are just turning analog resistors on/off with switches) You buy 5% accurate components everywhere then just trim the errors down to 0.01%. Not easy per se, but 99.99% accuracy is doable at the student level with the right designs. Professional level precision analog designs are the 7+ digit multimeters (99.99999% accuracy). Yes, built out of just 1% accurate parts. If you need matching pairs, they make specially matched resistor chips or whatever. -------- The concepts aren't hard btw though maybe slightly out of date. The book Art of Electronics analyzes a 7+ digit accurate multimeter design from Agilent or something. Instead of using an analog pot to tune, today you'd use a digital pot. Otherwise, I'm pretty sure the overall analysis and technique holds in today's electronics market.

lbourdages 2y ago
Interesting. Would that be doable at a VLSI scale? I imagine that for large scale analog computers (like, neural networks) all these trimpots would become a challenge...
- dragontamer 2y ago
  True. VLSI does have techniques though. A clocked capacitor can sorta-kinda act as a trimpot if you calibrate the clock for example. And capacitors and clocks are more amicable to VLSI.