Hi John, As general guidance, traces should be kept as short as possible, and as straight and direct as possible. Small value resistors near the driver, such as 22 ohms on all lines, help reduce signal overshoot and ringing. You may also want to route the SPI lines over a ground plane or pour, and keep the SPI lines separate from other switching signals to reduce crosstalk. Regards, Joel
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Forum Post: RE: ADS7047: SPI Interface
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Forum Post: RE: ADC12DL2500EVM: companion capture boards
Agreed, let me know if you have any other questions. I will close this post for now. Or you can start a new post with a separate question. Regards, Rob
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Forum Post: RE: ADS7138-Q1: Abnormal read register value, unable to successfully write register
Hi Ziming, ADC conversion data can be read in two ways: 1. Initiating a read to the device (Figure 8-13) 2. Reading from the RECENT_CHx_LSB and RECENT_CHx_MSB registers. This requires first setting the STATS_EN bit to 1 to enable updating the registers. You also need to set the CNVST bit to 1 if you will only be using register accesses to convert. A single register read is described below. So at the moment, it seems like setting the CNVST bit in the GENERAL_CFG register is still missing. The device has not initiated any conversion at the time of reading back from the registers, so there is no conversion result. Regards, Joel
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Forum Post: RE: ADS7028: Maximum input frequency
Hi AhmadBashar, For this, I suggest referencing our TI Precision Labs videos, specifically the SAR ADC input driver design videos. I've linked the first video below. They provide comprehensive guidance to designing the front end ADC circuit. Feel free to follow up with any questions that might arise. https://www.ti.com/video/5476574757001 Regards, Joel
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Forum Post: RE: BP-DAC11001EVM: Unable to change output at TP6
Thank you Sanjay! I'm able to set the output now. Updating the patch file was what I needed. Best, Joe
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Forum Post: RE: TXB0108: TXB0108 - Open drain pin support
Hi Jeeveth, No concerns for TXB IC. It is more so compatibility concerns with the open drain I/Os that the TXB is interfacing with, as the device was not intended to be used for open-drain applications. The reason for >50kohms pullups suggestion is to avoid the VOL levels from being heightened due to internal 4k series resistance, as seen in https://www.ti.com/lit/an/scea054a/scea054a.pdf?ts=1744735358188 . Regards, Jack
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Forum Post: RE: ADS127L18EVM-PDK: TDM mode configuration
Hi Markku, Your configuration looks correct. If you can get a logic or scope capture of FSYNC, DCLK, and DOUT0, that would be helpful to debug the data. In your configuration, for each FSYNC rising edge, you should get CH0 data immediately followed by CH1 data. In other words, the first 4 bytes will be CH0 and the next 4 bytes will be CH1. You are also getting CH2 through CH7, but since these channels are powered down, you will just get 0x00000000h for each channel. Each of the channels will look like the below data packet frame, which includes the STATUS byte (no CRC), for a total of 32b. Regards, Keith Nicholas Precision ADC Applications
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Forum Post: RE: ADS127L11: Voltage reference changes are ignored when using the THS4551 FDA
Hi David, The ADS127L11 is sampling at 12.8MHz, and then digital filtering, so it is capturing the average value and filtering out the oscillation. The THS4551 has a very high bandwidth, and you can get stability problems if the feedback network uses very high value resistors. You may want to use 1k and 100Ohm to make sure this is not a stability issue. If this does not make the circuit stable, then you may have an assembly error that needs corrected. Regards, Keith
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Forum Post: RE: ADC121S021: ADC121S021 with Op-Amp
Hi, Kindly provide the update on this so I can proceed with my schematics design. Thank you
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Forum Post: RE: DAC39RF12: DAC39RF12-EVM
Hi Venu, Please see attached. The EVMs should be in stock this week, if not already. Regards, Rob e2e.ti.com/.../DAC39RF12EVM.zip
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Forum Post: RE: DAC39RF12: DAC39RF12-EVM
Thanks Rob.
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Forum Post: RE: DAC39RF12: DAC39RF12-EVM
Hi Rob One more question, which one will be in coming into stock DAC39RF10EVM or TRF1108-DAC39RFEVM or DAC39RF12EVM ? I appreciate if you could let us know so we are good to move forward procuring these. Regards Venu
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Forum Post: RE: DAC39RF12: DAC39RF12-EVM
Hi Venu, The DAC39RF12EVM will be in stock. The DAC39RF10EVM is going obsolete, the RF12 is the same DAC, just a different speed grade. I don't know about the TRF and DAC EVM. Regards, Rob
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Forum Post: ADS1291: How realistic is a two lead BCI wearable on the head? specifically for alpha/beta/delta/theta/gamma and potentially heart rate. How would you change my approach?
Part Number: ADS1291 Tool/software: Hi there, I have developed a head worn bci wearable using the ADS1291 assuming i would be able to pull out brain waves in a low accuracy manner. This is not a medical device, more of a fun consumer electronic low accuracy device. I still want to pull out truthful signals though. I've configured the ADS1291 in bipolar +1.8/-1.8v low noise analog power supply. along with the IN1P and IN1N as a differential input. two leads, near the temple. I'm also using the ADS1921 development board to evaluate and I'm noticing a few things that concern me. I am not certain that the signals im seeing are differential from noise. Using the realtime display and also the FFT/ Analysis display i can narrow in on the specific frequency ranges in each category. i am seeing frequencies that do match Gamma (30-100 Hz), Beta (12-30 Hz), Alpha (8-12 Hz) ,Theta (4-8 Hz) and Delta (0.5-4 Hz) but they all look very busy, im not sure if this is just complete nonsense. I am also able to narrow down the frequency range to identify what looks like heart rate. is there a better approach then just fft/highpass/lowpass to isolate a waveform or am i cherry picking noise, am i being naive here? One big issue i see is that i seem to be picking up the bodies coupling to natural ground. When i lift my feet off the ground the signal is a jumble of noise. and then i touch the desk or put my feet on the ground, the signal quiets completely. My question here is 1) what is happening when im touching physically grounded objects? is this because the development kit is grounded through a computer usb? would a battery powered self contained device not see this effect? 2) is my approach with a IN1P/IN1N differential amplifier configure setup realistic for something like this or should i configure the leads differently? 3) I see that the evaluation board says "for 2 lead operation make these component modifications" How is this different from using the RA/LA connections and Lead1 setting in the software?
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Forum Post: AMC7908: Is there a datasheet for the AMC7904RGET?
Part Number: AMC7908 Other Parts Discussed in Thread: AMC7904 Tool/software: I am unable to find any datasheet for the AMC7904, even though I have seen it referenced as being active. Has this part been released? Can we get a copy of the original AMC7904 datasheet for reference? If the part was not released, what is the substitute?
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Forum Post: ADS131M08EVM: Layout details of TP1 and TP2
Part Number: ADS131M08EVM Tool/software: Hello Team, Could you please share information on where TP1 and TP2 are on the ADS131M08EVM ? I don't see them on Layout sections in ADS131M08 Evaluation Module User's Guide (Rev. A) Best Regards, Akhil Bandi
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Forum Post: RE: ADS1256: ADS1256 ADC Circuit Design Review - 0.1-20 Hz Signal Sampling at 100 SPS
I have taken your suggestions into account and tried to use more up-to-date components
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Forum Post: RE: AFE882H1EVM: AFE882H1EVM Supporting
Elisha, I was able to get the EVM to work on my laptop by making sure that the driver was installed. This is a driver for the FTDI device on the board. Just to be sure, uninstalled the AFE88xH1EVM GUI from my laptop to start. Then I re-installed it. Make sure the EVM is not connected to the computer during the install. After that I ran the FTDI driver install that I mentioned. /cfs-file/__key/communityserver-discussions-components-files/73/6646.CDM212364_5F00_Setup.exe After that, the EVM worked correctly. The FTDI driver install was mistakenly omitted from the install package, so this separate install should clean up the problem. If the download from this e2e post does not work, then one option is to download the GUI for another EVM that uses the same drivers. You can download the GUI for the DAC8811EVM (which uses the FT4222H) which has the option to install the same drivers. You can find the DAC8811EVM GUI download here: https://www.ti.com/tool/DAC8811EVM Let me know if this helps you. Joseph Wu
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Forum Post: RE: ADS1261: Responding with All Zeros Part 2
I got chip select to work but when chip select is working the 1261 does not echo the command. The following graphs demonstrate this. By comparison, this is my software version 337 in which I was able to get the reset command to respond DIN 0x06, 0xFF DOUT 0xFF, 0x06, and other single commands work but RREG, WREG and RDATA do not reply. The graph shows the correct response on DOUT without any action on CS. The next graph is from my most recent software 346 which shows a good SCLK, DIN, CS but DOUT goes high and stays high thus not responding to the reset 0x06, 0xFF. This graph is also for software 346 CS is wider and does not exactly match the clock, I don't know why this changed, DOUT mirrors CS and does not respond to the command. This is a magnify of the same capture showing more detail in the clock which looks good to me and a good reset on DIN (SPI BUS MOSI) 0x06, 0xFF but nothing on 1261 DOUT. I also tried hardware reset on the 1261 RESET pin before every command but this had negative impact. I also tried cycling through all bus slave channels, 0, 1, 2 and I got a few reset commands to go through but then it stopped working and refused to start working again. At this point I have one software version with limited success, 337, which fortunately is checked into GIT, which will send about 100 failed reset commands before the 1261 starts responding correctly to them with good reset echo on DOUT and then it will respond to individual commands such as NOP, START, STOP LOCK, UNLOCK. But as soon as it gets a RREG command it stops communicating and will no longer work even on the RESET command which previously worked. I think your suggestion about getting Chip Select programmed properly was a good one but functionally it actually made it worse. On that software build 1261 did not respond at all even though CS does what it should in relation to CLK. I suspect CS should be tied active low because that is what it looks like when it works. I am confident my clock polarity is correct because the only way I could get it to respond at all was for the SPI BUS to latch on the clock leading edge so the 1261 can sample on a stable falling edge as I think you mentioned above. What is mystifying to me is that even when CLK and DIN are run perfectly the 1261 simply refuses to respond. At this point there is nothing else I can try in the software. And unless you can think of some way to get the 1261 to talk I will wait until we get our development board before proceeding. Sincere thanks for your time on this. Everett
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Forum Post: RE: AFE882H1EVM: AFE882H1EVM Supporting
Elisha, Sorry, my original post used the wrong name for you. I had written a similar message for an FAE, who I think may be working with you. Joseph Wu
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