In the field of semiconductor chip storage,SRAM and DRAM are two widely used volatile memories,and they are also the core storage components of various digital devices and computing hardware.Both of them have the characteristics of power failure and data loss,but because of the essential differences in internal storage architecture and working principle,they have distinct differences in core performance such as running speed,power consumption,capacity and cost,and their adaptive application scenarios are completely different.
 

Static random access memory(SRAM)is the core choice for high-performance storage scenarios.SRAM relies on bistable flip-flop structure to latch data,and the mainstream adopts 6T transistor cell structure.Through the combined circuit of cross-coupled inverter and NMOS transmission tube,binary data can be stably distinguished by the on-off state of transistors.The unique circuit structure allows SRAM to keep information stably for a long time without periodically refreshing data,with only static power consumption caused by tiny transistor leakage current,and at the same time,it has nanosecond speed access capability of 1-10ns,which is widely used in chip cache,high-end computing equipment and other scenes that require extremely high response speed.
 

DRAM,also known as dynamic random access memory,adopts a minimalist 1T1C cell design and records data by storing charge in a capacitor.However,the capacitance charge of DRAM will continue to leak naturally,usually in tens of milliseconds,so the device must complete the data refresh operation every 64ms,which also makes DRAM generate high dynamic operation power consumption.
 

The structural differences of storage units directly open the comprehensive gap between them.The 6-transistor cell of SRAM is huge,and its cell area is 4-5 times that of DRAM.Under the same chip area,the storage capacity of SRAM is much lower than that of DRAM.Taking the 45nm process as an example,SRAM with 128Mb capacity will occupy about 70%of the chip area,while DRAM with the same capacity only needs one-fifth of the area.On the other hand,the access speed of DRAM is only 50-100ns,which is far inferior to SRAM.
 

On the whole,SRAM has complex architecture and high cost,but it is fast and simple in system integration,focusing on high-performance scenarios;DRAM is the first choice for large-capacity memory with high space utilization and outstanding cost performance.With their differentiated characteristics,DRAM and DRAM support multiple applications in the semiconductor storage industry.

Keywords:SRAM,DRAM