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TPS92520-Q1: Should we must use input undervoltage protection?

Part Number: TPS92520-Q1

I mean just use MCU to directly control the UDIM pin for ON/OFF.

but if unfortunately  have a very noisy input such as a 12V with 3V 1KHz ripple, then some ripple on Boost (VIN for TPS92520) and on V5D. Is there any risk?

What is protected by this input UV protection?

  • Hello Haigu,

    You have a boost converter so that output should not be that noisy with minimal ripple.  You don't have to have the UVLO circuit on 520's UDIM pins but then you should do UVLO protection as part of your MCU poling algorithm.  The 520 has a ADC to give the MCU input and output voltage measurements, which allows for MCU to do intelligent control of the outputs.  We only want to turn on the output when the input voltage is at least 3V above the expected output.  I generally like to see 5V of overhead.  Some people dynamically change the BOOST voltage based on those ADC measurements.  This is a system level assessment that you must make.  We just give you the tools to make those assessments.  I like having the UVLO circuit on UDIM because it frees up the MCU, but it does cost money because of the component cost, pcb space, and assembly costs.  That is something you guys must access and determine if your system needs it.  If you are driving LEDs then if you run the 520 in drop out then you will be seeing the light as abnormal.  It won't be in a condition that it works correctly and that might not be acceptable to the end customer visually.  Nothing will get damaged because we have fault protections incorporated into the part, but this is might not be acceptable in your system.  I don't have access to your requirements so that is something you need to access and plan accordingly.  Let me know if you have more specific questions or let me know what your requirements are and then I can help let you know if you might want to do UVLO protection in hardware or software.


  • thanks.  this protection is to provide enough input overhead for buck.