Memory design: digital or analog?

[noviceca]

Hi,

I will have an interview with a company which designs memory. I am kind of confused: memory design engineer deals with analog design or digital design?
Will anyone enlighten me so I can prepare accordingly?

Thanks for your help!

 

[bilalkadri]

memory design involves SRAM, EEPROM and ROM. each has different criteria to be evaluated upon.

for SRAM, look into transistor sizings of the six transistors of a 6T sram cell. in sub-micron range these sizings are flexible.

for EEPROM, look into how high voltage (for erasing and burning) is tackled with.


we write and read data simultaneosuly so cross talk may also be a problem in any high speed memory design.

 

[Fom]

Digital designer today use synthesis tools and RTL description of design. For simulation he uses Verilog or VHDL models. They don't need to know device physics.
RAM designer more close to analog because he used Spice-like simulator and Spice models.
Unlike analog designer he never will run AC analysis. But he should develop and verify Verilog or VHDL model of designed memory. So he should know HDL languages like digital designer.

 

[timo67]

Hi noviceca
Analog memories do exist
They are used to store a small number of samples (few hundreds) of very fast signals
In the order of the Nano second (1e-9 S).

An example of analog memory is realized by switched capacitors each capacitor will contain the analog value of the signal... This is the write cycle. Then you have the read cycle where each capacitor is read with an adequate Op Amp and appropriate circuit.

 

[dingjingfeng]

both, I think

 

[renwl]

more digital than analog, i think.

 

[suhas_shiv]

Its a mixed signal design. The analog part is the sense amplifier and charge pumps. Though I think there is more of digital design involved in memory design.

 

[shaikhsarfraz]

Memory cells have a lot of part, varying from Flip Flops(digital part), to sense amplifiers(analog)

 

[nwuedu]

It design with analog.But popular use in digital.

 

[noviceca]

Hi,

Thank everyone for sharing your opinion.

Today I met with a manager in that company. He told me in his group, design work involves 80% digital and 20% analog. For design time, 50/50 though.

Thanks again!