About Flash Technology

Technology Overview   |   Things to Consider When Buying   |   Flash vs. Other Options

Flash memory is well known today because of the popular flash memory cards used in digital still cameras. Flash memory is also used in many electronic devices including PCs, cell phones, PDAs, Ethernet adapters, network routers, cable TV set top boxes, and video game consoles.

Flash memory is a transistor technology. A single flash memory cell is made up of two transistors. One transistor is a floating gate and separated from the other transistor (a control gate) by a thin oxide layer. In the normal condition (no stored data,) electrons flow freely from the floating gate to the control gate. In computers, data is stored in binary terms - as ones (1) and zeros (0) - and the free-flowing electronic condition has a value of 1.

To store data, a value of 0 is created by applying low voltage to the floating gate and exciting the electrons, The electrons are pushed through the thin oxide layer and are trapped on the control gate side, where they block the connectivity between the control gate and the floating gate. To return the cell to a normal condition of 1, an electric field is applied to the cell and the electrons are restored to the floating gate.