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REF3030: Appropriate Vref to couple with 374S with same accuracy as Vref internal to DSP F28334

Part Number: REF3030
Other Parts Discussed in Thread: REF5030, , LM4050-N

Hi,

My customer needs to replace F28334 with TMS320F28374SZWTT.

Currently they acquire an analog signal via the internal ADC of the DSP using the internal Voltage Reference of 28334 and the accuracy of the measurement is ok for customer.
The new DSP 374 instead requires an external voltage reference.
I therefore need to understand the accuracy of the internal voltage reference of 28334 as it is not explicitly stated in the datasheet.


Customer needs this parameter to then choose the most appropriate (and not unnecessarily expensive) voltage reference for the 28374.
In the evaluation board of 28374 TI uses a very powerful voltage reference (REF5030IDGKT at $ 3.15), surely because the ADC of 28374 is much more accurate than that of 28334 but customer is interested in maintaining the current accuracy of 28334 therefore customer is looking for some suggestions to combine a less expensive voltage reference (example REF5030AIDGKT at $ 1.29 or a REF3030AIDBZR at $ 0.48).

Any comments here? You can also reach me in private for further discussions.

I also posted the same question in the C2000 forum: https://e2e.ti.com/support/microcontrollers/c2000/f/171/t/850370 

Many Thanks,

Antonio

  • Hi Antonio,

    The F28334 has an internal 12b ADC that has lower voltage reference requirements which is why the internal reference can be good enough for certain applications.

    The F28374 has an internal 16b ADC that has much higher voltage reference requirements if the customer wants to take full advantage of the 16b ADC.

    The REF3030 will work fine for your application if they are already used to a 12b ADC. The EVM is using the REF5030 to demonstrate the accuracy and low noise of the 16b ADC.

    The F28374 can use a 2.5V or 3V VREF. If they want something lower cost, the LM4050-N in 2.5V option will also work and be better than the internal VREF of the F28334.

    -Marcoo