2Mhz sampled differential ADC with fast FFT (Hardware? Options?)

[CarlFST60L]

Hi All,

I have been using successfully the uTasker FFT solution on a K64 but have hit the limit of raw processing power. I can perform 400Khz ADC sampling and get 512 amplitude bin output (0 -200Khz). The uTasker solution gave us DMA sampled ADC with ping pong buffers and the ARM FFT library, it works great, but the processor cannot get the performance we need.

We need to increase that performance 5 fold at least. We would like to sample at a minimum of 2Mhz and still have overhead to do some software analysis  and communications and still do 1024point FFT's. 

I can only imagine now we need some hardware FFT module. Are their Kinetis processors that will do this? Or are there external modules that we can connect to the processor? I have found some TI / Analogue devices parts that will do all this but would like to stick with the K series if possible.

[jingpan]

Hi Carl,

Thank you for your interesting in NXP product.

There isn't any part which can support 2M sample rate in K series. I have 3 candidates for you.

1. Kinetis KV5x MCU. It has a CORTEX-M7 core with 240M frequency. 2 12bit high speed ADC sampling at 5 mega samples per second (MS/s).

2. LPC546xx MCU. It has a CORTEX-M4 core with 220M frequency. A 12bit 5 MSPS ADC.

3. LPC540xx MCU. It has  a CORTEX-M4 core with 180M frequency. A 12bit 5 MSPS ADC.

Since NXP and Freescale has merged for a long time, their IDE also merged. Now you can use MCUXpresso to develop both Kinetis and LPC54xxx.

Regards,

Jing