Introduction of DRAM and SRAM memory principle
DRAM is the abbreviation of Dynamic random access memory. It is applied in the system with undemanding in power dissipation, larger capacity of system cache and faster speed.
It is generally used in kinds of electronic system, such as PC, communication, DVB, LCD TV, monitoring and so on.
Below is sort of DRAM:
DRAM, Dynamic random access memory, is the production being obsolete.
SDRAM, SynchronousDRAM, is mainly used in PC.
DDR SDRAM, DoubleDataRate, is mainly used in PC.
RDRAM, Rambus DRAM, is less used in PC compared with DRAM.
SRAM is Static Random Access Memory. It has static access and stores internal data without circuit refreshing.
SRAM is mainly applied to system with smaller cache or system requires power dissipation. For example, many 8 bit MCU support smaller RAM and insufficient cache. And 16 BIT MCU supports system with larger RAM and system demanding power dissipation but not available for DRAM.
The difference between SRAM and DRAM
| SRAM | DRAM |
Structure | There are 6 transistors in each memory cell, GIGADEVICE has 2 transistors each unit but with a big current in standby. | There is one transistor in each memory cell and DRAM needs refreshment |
Operating State | 10mA-30mA | Over 100mA |
Standby | 1uA-20uA | Over 10mA |
Access Speed | The faster access speed is about 10nS, 12nS ro 15nS, and the slower one is about 55nS or 70nS. | Access Speed is as fast as 10nS or below. |
Capacity | The maximum capacity is 16M BIT. | Monolithic achieves 512M BIT. |
Application area of SRAM
Application Area | Communication, instruments and so on | Electronic dictionary, POS, printer, game machine, instruments and so on | Over 10mA |
Capacity(BIT) | 256K, 1M, 2M, 4M | 256K, 1M, 2M, 4M, 8M, 16M | As fast as 10nS or below |
Capacity | The maximum capacity is 16M BIT. | Monolithic achieves 512M BIT. | |