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REF5050: How to improve the noise performance

Part Number: REF5050
Other Parts Discussed in Thread: REF54

Hi team

for the REF5050, how can we improve it’s noise performance ?add a RC filter ?and add a follower after the RC? but the follower need to be more precision in noise performance? 

  • For the amplifier, its noise may not be lower than the reference ? so will this cause the noise be worse?

  • Hello,

    There are multiple ways to improve the noise of REF5050, the best of which I have explained below. What is the application for REF5050 here? What noise performance are you expecting or hoping to obtain?

    1. New pin-to-pin replacement REF54: Improved noise (0.45 ppm p-p or 0.11 ppm p-p with filtering), and pin to pin with REF5050 when TEMP pin not used. More information at https://www.ti.com/product/REF54 

    2. TRIM/NR Pin: Adding a capacitor from the TRIM/NR pin to ground can improve output noise levels. More information about this can be found in section 9.3.4 of the datasheet:

    3. Equivalent Series Resistance (ESR) of Load Capacitor (CL): As stated in the datasheet, the equivalent series resistance (ESR) value of CL must be less than or equal to 1.5 Ω to ensure output stability. To minimize noise, the recommended ESR of CL is from 1 Ω and 1.5 Ω... If the ESR of the capacitor is not enough, then an additional resistor must be added in series with the output capacitor. A resistor in series with the output capacitor is optional.

    4. Layout guidelines (section 12.1 of datasheet): A high-frequency, 1-μF capacitor can be added in parallel between the output and ground to filter noise and help with switching loads as data converters.

    Depending on what the noise level that you are trying to obtain, one of these options might be better than the others.

    Thanks,

    Jackson

  • A buffer amplifier is typically used on the output of a voltage reference when a high sampling rate is being used when attached to an ADC. It will add to the noise, so if this is needed, a low noise, low offset buffer should be used. Is REF5050 being used with an ADC or DAC?