This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Part Number: LMH6517
I am trying to program the gain of the LMH6517 via SPI using a beagleboard, but that does not seem to work. I already checked the communication lines on the oscilloscope and everything seem fine, so I would like to know if anyone can help identify what the problem is.There is some fixed gain there because I get an amplified signal out of it, but it does not change. The latch pin should not matter when spi is in use so I wonder what could be happening.
This would be the python code:
from Adafruit_BBIO.SPI import SPI
spi = SPI(1,0) #configure device and bus at beagleboard
spi.msh = 10500000 #clockspi.bpw = 16 #bits per word
spi.open(1,0) #opens it
spi.xfer2([128,0]) #transmits data
In reply to JPL:
It was just a probe issue here, the signals are correct... I am back to the start.
Since I get the signal transfer if I use just the beagleboard and connect MISO/MOSI together, the problem would not have been there I guess.
On page 13 here the SPI settings are given, I tried changing the mode before and it didn't help. Just to be on the safe side, it should be mode 3, am I right?
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.
Jacob Freet High Speed Amplifiers
In reply to Jacob%20Freet:
Hi Jacob Freet,
Even when sending like that the chip does not respond, I get the same constant gain when sending these commands for example:
I redesigned my board to use the LMH6517 on pulse mode, I don't know what is happening with the SPI. I tried programming a different PGA here that I also designed a circuit using SPI and for the other one my code worked, so I guess the LMH6517 requires something else that I was not able to find out.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.