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LM4132: Creating Stable and low noisy Vref for high speed ADC

Part Number: LM4132
Other Parts Discussed in Thread: REF35, REF4132,

Hi

I have a high speed adc design(ADC 3669) which requires the reference voltage of 1.15 for which i followed a approach from one of high speed adc EVK as below

kindly let me know if there are any other alternative or better approaches(if any), kindly drop comments on my approach also

  • Hi Shyam 

    You are using resistor divider with 1% tolerance, this will contribute to >2% error in the reference voltage . Are you doing inhouse initial calibration?

    Is there any specific reason you are using 1.15V?  We will be releasing REF351200QDBVR soon which will have reference voltage 1.2V with 0.05% initial accuracy 12ppm/C tempco and 3.3 ppm pk-pk flicker noise. 

    Can you please comment on below questions and we can come up with optimum solution . 

    • Can you please confirm ADC part no , ADC366X. 
    • What is the ENOB for signal chain and what is the temperature variation? 
    • What is the error budget for the VREF? 

    Regards

    Trailokya 

    • Can you please confirm ADC part no , ADC366X. 
      • its a new ADC of TI which is not released yet, kindly reply to my mail id shared in private message
    • What is the ENOB for signal chain and what is the temperature variation? 
      • not sure about ENOB at this point, in othe words bit error up to 2-3 bits is ok, as the ADC is 16bit
    • What is the error budget for the VREF? 
      • 3 bits would correspond to 50uV roughly i assume, 

    Considering above can i replace LM4132 1.8v output with REF35 or REF4132

    only problem is the 1.8V version is out of stock 

    Kindly help with proper configuration, provided samples or stock are available for suggestion 

  • HI Shyam 

    Thanks for the information. Let's discuss it in more detail over mail. 

    Regards

    Trailokya