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ADS1158: Crystal for ADS1158 EVM, ADS1258 EVM

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Replies: 2

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Part Number: ADS1158

Hello Sir,

Currently, I make a ADS1158(or ADS1258) based DAQ board with reference to the ADS1158 EVM board (ADS1258 EVM).

I used same capacitor value and same crystal(load capacitance, ESR) to my DAQ board, but it does not provide clock signals.

Sometimes, It generate the clock signal only for short time about less than 20s.

I did many things to make clock signal as explained below. 

 1) Low temperature soldering for short time

 2) Crystal soldering carefully to do not damage the crystal structure

 3) Change the crystal to other product (same specification, just different manufacturer)

Even I change the crystal on ADS1158EVM, it does provide clock signal only for short time about 10s as same situation above.

Could you give me advice to make clock signal to ADS1158?

Is there any specific crystal ADS1158 EVM using?

Best regards,

Dae-Jin Kim

  • Hi Dae-Jin,

    If you search E2E for "ADS1258 Crystal Startup", you'll notice that this is a common problem and kind of a finicky circuit to tune. Even when using the recommended crystals per the ADS1158 datasheet, I've seen people recently run into issues with these crystals that we formerly tested and didn't encounter any issues with. 

    I have some suggestions for how to deal with this issue on this E2E post which might be helpful: https://e2e.ti.com/support/data-converters/f/73/p/628309/2321778#2321778. Crystals with lower ESR values seem to work best (I recommend less than 50 kOhm ESR).

    In truth, I think the easiest solution is to avoid having to tune the crystal + oscillator circuit and just prove a direct clock source to the ADC. Using a oscillator (with a built in crystal, for example such as can be found here https://www.digikey.com/short/p050ch) simplifies the design and avoid having to go through the process of validating that the crystal circuit will work over temperature.

    I hope that helps.

    Best regards,
    Chris Hall
    Applications Engineer | Precision ADCs

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  • In reply to Christopher Hall:

    Hi Christopher,

    Thank you for your comments.

    As you mentioned, I will try to use the oscillator (16Mhz) that connected to CLKIO pin at ADS1158/ADS1258.

    Dae-Jin Kim