Digilent Analog Discovery 2 record mode limiation

[LukeChen]

I need to capture the signal which is must be sampled in 25Mhz for avoiding  aliasing.

But while I use record mode to capture it, WaveForms keep showing message "reduce sample rate".

For 25Mhz sample rate, and 14 bit resolution, data rate is 350Mbps

AD2 is using USB2.0 which should transmitter data up to  480Mbit/s.

AD2 should continues record 25Mhz data, the only limitation is my PC RAM size.

Is my understanding correct ?

 

[attila]

Hi @LukeChen

The 480MHz is the USB 2.0 frequency, which uses some of this for sync and other usb protocol transfers, control...
The maximum USB bulk IN bandwidth is about 40MBps, 370Mbps for large data transfers.

In the AD2 the bandwidth is shared between various instruments, so the record is performed in small chunks which reduces the rate to about 1-2MHz

 

[LukeChen]

Thanks so much for your quickly response. Might I decrease  resolution to 8 bit or insert some memory inside. Or do you have a product which support USB3.0 and more memory buffer.

[attila]

Hi @LukeChen

The software does not provide option for 8 bit sampling. We don't have device with USB 3 or more scope buffer, yet.