What is Dynamic Random Access Memory?
Dynamic random access memory, or DRAM, is the most common type of computer memory. It is particularly useful for computers as it can hold a lot of data in a small physical space. However, it does not usually retain data when its power supply is switched off, meaning that it isn’t suitable for permanent storage. Random access memory simply refers to memory where any piece of data can be accessed almost instantly. This is in contrast to storage media such as cassette tapes where the data can only be accessed in a fixed sequence. The “dynamic” element of DRAM is that its power supply must be constantly refreshed for it to work. This distinguishes it from static random access memory or SRAM. Both SRAM and DRAM work by holding information in binary format, meaning it is broken down into 1s and 0s. With static random access memory, this is done through an electrical current which can be switched into two different directions. With dynamic random access memory, this is done by series of cells
(DRAM) A type of {semiconductor} memory in which the information is stored in {capacitors} on a {MOS} {integrated circuit}. Typically each {bit} is stored as an amount of electrical charge in a storage cell consisting of a capacitor and a {transistor}. Due to leakage the capacitor discharges gradually and the memory cell loses the information. Therefore, to preserve the information, the memory has to be refreshed periodically. Despite this inconvenience, the DRAM is a very popular memory technology because of its high density and consequent low price. The first commercially available DRAM chip was the {Intel 1103}, introduced in 1970. The early DRAM chips up to a 16k x 1 (16384 locations of one bit each) model needed 3 supply voltages (+5V, -5V and +12V). Beginning with the 64 kilobit chips, {charge pumps} were included on-chip to create the necessary supply voltages out of a single +5V supply. This was necessary to fit the device into a 16-pin {DIL} package, which was the preferred pa
