Gregory's Server@kenshirriff There's something I never realised I didn't know: how does an EPROM actually work at the component level? (And is it related to the thing about not being able to take flash photos of an uncased Raspberry Pi without it crashing?)
|
5 comments
 @kenshirriff Thanks! So the programming voltage is applied across the gate and drain, and is sufficient to temporarily break down the resistance of the oxide? Then the surplus electrons sit in the depletion layer, making it not depleted any more, and allow current to flow between source and drain?  @darkling Yes, there's a diagram at Wikipedia: https://en.wikipedia.org/wiki/EPROM#Operation  @neffo @darkling Yes, although gamma rays will mess up most chips. |
@darkling The quick explanation is that an EPROM has a transistor with a"floating" gate for each bit. You program a bit by forcing electrons through the insulating oxide with high voltage, and the electrons are trapped there. Ultraviolet causes ionization in the oxide, releasing the electrons and erasing the chip.