How to communicate with external ADC which up to 200 Msps or more??

[JLe]

Hi all, I hope someone could help me on this.

I have a trouble on read out ADC from a signal 1Mhz, and my current MCU can't read ADC with this high frequency signal. So I decide to use external ADC IC.

I found some from Analog device which can support this task.

But how can I read back the data from ADC IC since the frequency is much higher than the MCU.

If anyone have face this issue could you please share with me on this. Many thanks from your great help!

[S.Ma]

STM32 usually has multiple ADCs for the same input pin. This means you can combine ADC IPs to boost the sampling rate to 1 Mbps. This is documented in the reference manual and there should be examples on how to use the feature in cube library project examples of the ADC.

If you use external ADC, the analog speed becomes a digital bus speed challenge.

A 16 bit ADC at 1msps requires 16MHz spi.

A 24 bit ADC at 1msps requires 24MHz SPI.

If on the same board, probably the SPI limit would be 48 MHz.

Faster requies parallel interface bus type ADC with romless interface. faster = wider at constant clock speed.

[Tesla DeLorean]

Going to be a challenge, heh? Have you tried drinking from a firehose before?

Honestly where are you going to put the data, and what are you going to do with it?

Is this a sustained stream or one of finite/manageable length?

Perhaps look for FIFO memories (video/camera capture) you can clock data into at the desired rate, and clock out at a rate you can manage.

Build a memory subsystem that can capture/store? FPGA/CPLD, SDRAM

Use a PC base capture card?