What’s inside a flash drive?
In the age of technology, many of us wonder how this or that device actually works. I’m sure flash drives are no exception. Some of them are extremely small or come in funny shapes, but all of them perform the miraculous task of transferring and storing our most precious files.
So what makes them tick? What happens when they memorize or erase? What are the secrets that are hidden inside their casings? Luckily, we also live in the information age, so I’ll try to satisfy your curiosity.
The first thing to look at is the interior. If you have a transparent USB drive, you have the advantage here. But if not, you will have to open the case. There you will see a green circuit board, something familiar to most people, and two black chips. These are the main components. One is a microcontroller (usually on the right) and the other is a flash memory chip (usually on the left).
The first is the small version of a computer processor and the second explains the terms flash drive and memory card. But what is a flash memory? Basically, it is a technology that is electrical in nature but does not require energy to store data. It achieves this with floating gate (FG) transistors that reside within its memory cells.
The way such a transistor works is that it has this extra gate, the aforementioned FG, placed between the control gate and the channel area, separated by oxide layers. These layers make it possible for electrons, basically data, to be trapped and stored in the FG. To erase, a different set of voltages is applied which causes the electrons to be drawn out again. When a flash drive is plugged in, the commands given by the host machine (write/erase/read) decide what voltages are exerted to make the flash memory act the way it’s supposed to.
These processes are quite complex, so it’s surprising that chips have gotten smaller and more capable over the years, especially with the invention of multi-level memory cells. It reminds us of the rapid technological advances made with the processors of the larger companions of our flash drives: personal computers.
The largest USB stick on the market right now is 64 GB, but we should see the release of 128 GB flash drives soon. Samsung, for example, has promised one since last year. However, how such a large capacity can be achieved is a puzzle with current methods. So it is very likely that there are innovations involved. Time will tell!
