I am looking for a design house with dynamic memory device support. Design houses, I found on the web, support only analog, mixed-signal, high-voltage designs and so. I found no design house with dynamic memory support. Whatever I missed, I have no idea. To be honest, I am totally lost in the practice of the microelectronics industry.

Could anyone please point in the right direction, which design house should I contact? Also, thank you for any advice in advance.

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    \$\begingroup\$ In addition to the fact that sourcing / vendor selection questions are fundamentally not permitted here, there doesn't seem to be a lot of logic to your search. Making a custom dynamic RAM is almost certainly a bad idea - it's not a memory type that gets integrated with other functionality, so just buy it off the shelf as a distinct IC (or at least die), or use a memory type which does get integrated. If you mean board-level design, that's not usually what is meant by a design house. \$\endgroup\$ – Chris Stratton Jun 11 '18 at 22:38
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    \$\begingroup\$ It sounds like you are trying to make a PCB/system (although your terminology is confused). In that case, you want any design house that can handle "high speed digital design" -- which, depending on the speed of that DRAM, is probably most of them. \$\endgroup\$ – DrFriedParts Jun 11 '18 at 22:53
  • \$\begingroup\$ @Chris Stratton: so what is the best chance of a newbie to get help? \$\endgroup\$ – cocox Jun 12 '18 at 0:09
  • \$\begingroup\$ @DrFriedParts: I found design house with high-speed communication designs in their profile, also told me, memory is unlikely their interest. I will keep searching in that direction. \$\endgroup\$ – cocox Jun 12 '18 at 0:09
  • \$\begingroup\$ @cocox first you must clearly and completely state what you are actually trying to do. What exactly are you building? And why do you think DRAM will be a useful part of that? Your question currently has 3 close votes, meaning you probably have only about an hour, maybe less, to edit it into a rule compliant form. \$\endgroup\$ – Chris Stratton Jun 12 '18 at 0:11

[I will interpret your question as meaning design dram inside a custom ASIC chip]

DRAM is a specific foundry process (requiring HiK dielectrics and vertical features to maximise the pf/mm^2), not an option of a standard cmos process and foundry (as far as I know). In a custom chip I was making DRAM seemed like it might be a good idea, as 90% of the data was only transitory, and there would be no refreshing required.

In the end I found two problems:

  • Without the special (HiK, vertical) dram process, the dram cells are not especially small, as they need storage C.
  • The driver blocks are large - equal in size to about 32k of SRAM, so only a much larger array (eg >256k) could make any sense.

There did exist a couple of dram block designs for use in standard cmos processes. Any chip designer can buy/use them. From memory one was a multi-process IP block, and another was a standard IP block for one of the major foundries 0.18um processes.

Neither turned out to be at all useful for the smallish ram I needed, and there would probably be a pretty limited number of times they could make sense, as for bigger spaces, using an external dram and co-packaging the chips would be better.

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  • \$\begingroup\$ It will be great to use something more up-to-date process, something around 30 nm. Can you help me with that? The memory capacity of the device supposed to be 64 megabits or more, with reasonable mechanical dimensions, and standby current (below 1 mA at 60 celsius). \$\endgroup\$ – cocox Jun 12 '18 at 0:22
  • \$\begingroup\$ I suspect that dram was more attractive the bigger the cmos process. As the process gets smaller, the SRAM penalty of 6 fets and connections reduces as the square. However I suspect the area of the dram capacitor stays fairly constant (just reducing with the VDD). Someone more familiar with processes could comment... \$\endgroup\$ – Henry Crun Jun 12 '18 at 0:29

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