Jim, We are driving both VINI and VINQ inputs with same input to improve capture bandwidth in DESIQ or DESCLKIQ mode. I don't understand how second harmonic performance will be degraded by driving both VINI+ and VINQ+ with the same AC-coupled signal. With VINI- and VINQ- both AC-coupled to ground this should act like a typical AC-coupled application. With V_CMO connected to ground and the inputs AC-coupled the ADC12D1620 datasheet reports the DC-coupled and AC-coupled modes should perform similarly. Why would our proposed AC-mode implementation have degraded performance? Thanks, Kyle
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Forum Post: RE: ADC12D1620QML-SP: Single ended drive into the I/Q ports
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Forum Post: RE: Linux/FDC1004: FDC1004
Hi Kulatuch, I apologize that we cannot provide more help with your issue, but we do not currently support Raspberry Pis. I2C is a very common communication protocol, so any Raspberry Pi I2C library should work for you. If you think you may be having a hardware issue, feel free to post your schematics. We would be happy to help you debug them. Regards,
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Forum Post: RE: LM96163: Example configuration
Darren, The POR register settings are described in the datasheet. If you have the LM96163EBEVM + sensoreval SW you can play around with the register settings. The datasheet has instructions for setting up the fan controller. See " LM96163 REQUIRED INITIAL FAN CONTROL REGISTER SEQUENCE" on pg 21. -Kelvin
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Forum Post: RE: ADS114S08: PGA settings
Hi Harini, You didn't state what reference voltage you are expecting to use. If the reference voltage is the supply then the full-scale range (FSR) would be +/- 825mV (3.3/4) or +/- 625mV (5/8). These FSRs would seem to work based on a maximum input voltage of 600mV. But this rough calculation does not consider the input-voltage restrictions of the ADS114S08 . With unipolar supply and with the PGA enabled you cannot reference the shunt input to AGND as there are certain PGA input-voltage requirements (see section 9.3.2.1 on page 32 of the ADS114S08 datasheet). The input voltage and gain must abide by equation 5 in the datasheet. There is a calculator tool to help you understand as well as calculate your desired operation to see if the input restrictions affect the desired configuration. The calculator can be downloaded from: http://www.ti.com/tool/ads124s08-excel-calc-too l The above calculator tool will help you see the input range for the gain, reference voltage and analog supply chosen (Common-Mode Range tab). Using the PGA with a unipolar supply even at only a gain of 1 requires that the shunt voltage is offset greater than 0.15V above AGND as the maximum output of the PGA is 150mV from either supply rail. You could add a small offset, but the stability of this offset and any noise in the offset voltage will directly impact the result. With the theoretical value of 600mV maximum input voltage using a gain of 8 would seem possible to do using a 5V reference and 5V analog supply, but because of the input restrictions the common-mode of the input voltage will be too high to allow a gain of 8 with this type of configuration. Also, using a gain of 8 with a 5V reference has the same resolution as a gain of 4 using a 2.5V reference. The most gain that can be used with a 5V supply is gain of 4 due to the input requirements. Using +/- 2.5V bipolar supplies will allow the shunt to be referenced to AGND. When using the 5V unipolar supply and If the shunt is referenced to AGND (VINN is 0V at AGND), the output of the PGA using a 30 ohm shunt and 20mA of current will try to force the PGA outside of the supply rail. However there is an alternative to using this configuration. If the shunt is referenced to an offset voltage provided from the ADS114S08 you can simply the circuit. One source for this offset is the internal reference output. Using this 2.5V offset will allow the PGA to be enabled using a gain of 4. The 2.5V offset will unfortunately not allow for a gain of 4 with a 3.3V analog supply. However, it may be possible to use the VBIAS (which is mid-analog supply) as the offset. I have used the internal reference as a shunt offset, but I have not used VBIAS, so some experimentation will need to be done. If VBIAS does work as expected, then you should be able to use the PGA at a gain of 4 for both 3.3V and 5V. Option 1 would require PGA bypassed at a gain of 1. Option 2 would require an offset for the shunt with a gain of 4 possible. Option 3 would allow a gain of 4 and the shunt could be AGND referenced. Best regards. Bob B
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Forum Post: RE: ADS131A02: Issue on communication
Hi Michael, Sorry for the delay, I was out of the office for a few days. I agree that the device appears to have unlocked correctly, based on the fact that you can read 0x06550000 in the next frame. I don't understand why increasing the SCLK frequency would have solved the issue. I will recheck the timing specs and speak with the designers to see what we might have missed. Best Regards,
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Forum Post: RE: ADS1248: A/D data linearity under the IDAC-OFF situation
Hi Suzuki-san, You can contact me at the email address below: pa_deltasigma_apps@ti.com Best regards, Bob B
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Forum Post: RE: Camera Link Medium
Hi Victoria, 1). I did further checking and here is a good article about Camera Link specifications: en.wikipedia.org/.../Camera_Link 2). Also, here is a link to one of the Channel Link I devices - not II as I had noted - that could be used for this application: www.ti.com/.../ds90cr285 3). Also a link for all Channel Link I products: www.ti.com/.../products.html Regards,,,nasser
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Forum Post: RE: Linux: DAC7564IAPW driver was not found in Linux kernel
Riguang, I'm not intimately familiar with available Linux kernel modules, but a generic SPI module should be able to communicate with the DAC7564 so long as it has some basic configurability for number of clocks, clock phase, and clock polarity. The interface for the device is quite generic. Otherwise, we have not prepared kernel modules or drivers for the Linux environment for individual DAC devices or a generic high-level SPI driver. To be honest in large part this is outside of the expertise of the analog engineers we have on our team, but we can look into the development of something generic. Any inputs or suggestions you would have for a generic SPI driver could be helpful.
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Forum Post: RE: FDC2114: Using FDC2114 to discriminate touch vs objects
Hi Mihai, This is possible, as long as the objects are measured at a fixed distance from the sensor. This can be accomplished by placing an insulative layer over the sensor. Each object has a different dielectric, so they will induce different changes in the sensor capacitance (and therefore sensor frequency), which the FDC2114 will output in digital format. If the objects are held at the same distance each time, the different objects should produce different output codes. If the dielectrics are too similar or the objects are not held at a fixed distance, the device may not be able to tell them apart. Also note that the size of the objects will impact the measurement as well. Even different fingers will affect the sensor capacitance in different ways. It may not be feasible to differentiate every possible object from a finger, but it could be feasible to differentiate between a discrete number of objects with distinctly different dielectrics. I would suggest testing the application using the FDC2114EVM , which can be purchased on the TI store. Regards,
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Forum Post: RE: ADS1118: Analog input voltage range
Thanks for the background information Scott. Are you planning to use ADS1118 with an external Mux then or do you plan to use 6x ADS1118 ? The ADS114S08B comes in a 5x5mm QFN and could measure 12 single-ended signals for example. Regards,
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Forum Post: ADS1298: Problems with aVL and aVF
Part Number: ADS1298 Hello! I'm new to the ADS1298 /8R EVM Evaluation Software, I'm trying to make a few test signals, and when I create an input short to either Lead I or Lead II, aVL and aVF do not match with the definition provided by the manual (aVL = Lead I - (1/2)*Lead II, aVF = lead II - (1/2)*Lead I), because when Lead I = 0, aVF = 0; and when Lead II = 0, aVL = 0. I suppose it has something to do with the configurations of GPIO and OTHER Registers but I am not sure how to proceed. Any help is greatly appreciated. Thank you very much!
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Forum Post: RE: ADS8678: Common mode range
Hi Francesco, It's not a problem. Please let us know if you need any further support. Thanks for choosing TI ADCs. Best regards Dale
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Forum Post: RE: DAC8871: Precision Data Converters Forum
Hi Dukel, Yes, there will be some current flowing between the supplies/GPIO, but it is limited by the 10kΩ resistor. Even if the GPIO is 0V, there is 330µA flowing into the pin. You could also increase the resistor value to reduce this. Also, the purpose of the pull up is to set the state high if the GPIO is in the high-z state (input). Thanks! Paul
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Forum Post: TSW14J56EVM: Export/Convert Raw Data from HSDC Pro
Part Number: TSW14J56EVM I'm using a ADS54J60EVM with a TSW14J56EVM and am trying to save the data in the format typically plotted in the HSDC default screen (frequency(Hz) vs magnitude(dB)). The only options I see for exporting or saving data in HSDC is to either take a screenshot or save the "Integer Codes" as a .csv Any guidance on saving the raw IQ data or converting from Integer Codes to comprehendible data? Thanks, Reza
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Forum Post: RE: TSW14J56EVM: Export/Convert Raw Data from HSDC Pro
maybe even a "integer code" --> "time domain voltage conversion" ?
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Forum Post: RE: PCM1754: Noise problem of PCM 1754
Hi Liu, The power supply looks reasonably clean. I suspect this is digital cross talk issue from the layout. What are you using as SCK? I suspect that it is 1.22MHz. Please take a look at your PCB layout. Do you have a good return path for ground? Are the digital signals routed away from the analog output? Thanks! Paul
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Forum Post: RE: FDC1004QEVM: Way to Communicate with FDC1004QEVM Module with LabVIEW platform
Hi Vijay, I will communicate with you further about the Labview code via private message and will close this thread. Regards,
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Forum Post: RE: ADS131A02: ADC signal distorsion above 0.3V peak
Hi Victor, Thanks for the update. I was out of the office for a few days, let me look into this again and get back to you some time tomorrow. Best Regards,
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Forum Post: RE: ADS1118: Analog input voltage range
We were planning on using 6 ADS1118s. I had looked at the ADS114S08B but had ruled it out because at the time some of the signals were differential. Now that they are all single ended it makes sense. I will reconsider it. Thank you.
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Forum Post: ADC Evaluation Module with USB or LAN port
Is there any ADC Evaluation Module (or a series) equipped with USB or LAN port, that I can connect the board directly to a computer for data transmission?
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