5 ms·
While you marvel at this circuit remember that it was invented decades ago, for many purposes it is still state-of-the-art, and it costs fifteen cents.
by ebikelaw 8y ago
While you marvel at this circuit remember that it was invented decades ago, for many purposes it is still state-of-the-art, and it costs fifteen cents.
- IWeldMelons 8y agoTL0x4 latches in certain conditions, not quite state of the art behavior.
- Gibbon1 8y agoI worked on a motor controller that had a problem with PWM IC frying. Turned out the real problem was when the control signal was over-driven a comparator would latch up. Which would cause both power transistors to turn on. Blowing a 'protection' [1] fuse on the negative supply rail. And then the negative power supply would reverse. And kill the PWM controller IC. Not a fan of latching OP-Amps and Comparators. [1] Tip: fuses don't protect circuits from damage they prevent your POS from burning the house down.
- ebikelaw 8y agoPersonally I prefer to have parts that require external protection, rather than parts with robust internal protections that cost more or compromise the performance or that I have to hack around. It's more work, board area, and overall cost to have the external protections to keep an IC within its safe operating area, but I don't mind.
- hatsunearu 8y agoOh man, it's far from state of the art. "New" op amp features: - Crazy rail-to-rail input: some chips have onboard charge pumps to bias input stages such that you can input signals with common mode voltages far below and above the normal rails - Rail-to-rail output: probably the lowest hanging fruit of the "new" features, but still pretty costly - Stupidly high input impedance: 071 isn't completely blown out of the water but some of the new JFET opamps are nuts. I think there are like femptoamp class input currents these days. - Stupidly low offset voltage: I'm not even talking about the auto-zero ones, just regular old op amps have amazing performance these days.
- PhantomGremlin 8y agoNot only invented decades ago, but built decades ago. The "7949" on the chip means it was manufactured in the 49th week of 1979. Which is nearly 39 years ago. He's lucky to find a part like that. Today nobody is going to build a device in a 14-pin ceramic package and sell it for 15 cents.
- jstanley 8y agoI sometimes wonder whether integrated-circuit manufacturing wasn't sent to us by time-travellers from the future. Our ability to manufacture useful things, on such tiny scales, to such high precision, doesn't seem to match up with our comparatively-poor capabilities in other areas of manufacturing.
- vvanders 8y agoThere's a series on transistors that covers this. There's basically no mechanical process since everything is done via etching and litho. Leads to the results you see.
- pjc50 8y ago> comparatively-poor capabilities in other areas of manufacturing. [citation needed]
- HelloNurse 8y agoMany other things could be manufactured "on such tiny scales, to such high precision", but they wouldn't be useful. Integrated circuits are one of a few product/technology classes for which miniaturization is unconditionally good (improved power consumption, lower unit cost, possibly higher speed) up to unavoidable physical limits (e.g. randomly arranged doping atoms, noise vulnerability). Integrated circuits are also very easy to interface with the "real world" despite miniaturization because of their electronic nature: a comfortable range of currents and voltages is tolerable for the integrated circuit and acceptable for the larger system.