External FiFO or SDRAM for 5Msps ADC for 20ms

[lpcware]

Content originally posted in LPCWare by yoonghm on Fri Aug 14 16:32:11 MST 2015
Hi

  I am considering to use LPC54101 for a 8-bit 5 Msps ADC application for 20 ms. Is there any recommendation to use DMA to transfer those newly sampled data into external FIFO or SDRAM. LPC408x/407x come with external memory controller but not LPC54100.

Update:
  I think LPC4370, with external memory module, 12-bit ADC at 80 Msps would be a better choice. The challenge is the low-power operation. Any view?

[lpcware]

Content originally posted in LPCWare by bavarian on Wed Aug 19 05:56:49 MST 2015
[list]
  [*]  There is a significant price difference between the LPC54101 and the LPC4370
  [*]  Of course the LPC4370 consumes more power as the silicon is larger
  [*]  At 80Msps you will have a very high power consumption, but operation on 5Msps will give you reasonable power consumption (I don't know your target)
  [*]  If you have activity for 20ms and then go back to deep sleep for a second or so, then the power consumption of both chips will not be so different (provided that you know all the tricks for saving power). If you need to sample more often, then the LPC54101 clearly wins due to an optimized wake up time and some other tricks
  [*]  The project for a LPC54101 might be easier to handle, the LPC4370 is a pretty complex chip
  [*]  Low power and an external SDRAM doesn't really match, but as already said, I don't know your target
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