DRAM memory cells

[gregoost]

What are the advantages and disadvantages of building memory cells using MOSFETs instead of BJTs??? can any one help????

 

[dknguyen]

Power...and maybe size and cost.

 

[jangal]

mosfet use less power than bjts. the input ampedance is much greater. but bjt is faster.

 

[RCinFLA]

To the title, there are no bjt dynamic RAM's. BJT memory cells are alway static flip flops. Most common bjt memory is ECL (emitter coupled logic) used for their high speed. Use includes things like high speed digital storage scopes.

MOSFET dynamic RAM's use floating gate capacitance to provide memory. Since this charge eventually bleeds off it must be refreshed. The rate of discharge goes up versus temperature. A given cell at room temp may last for several seconds but to account for worse case IC processing and temp the typical refresh rate is in the order of a millisecond. Only significant supply current is used during reading, writing, and refreshing.

 

[gregoost]

Thank u very much guys..