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LM5164-Q1EVM: Input Voltage Range

Part Number: LM5164-Q1EVM
Other Parts Discussed in Thread: LM5164


I am currently reading the LM5164-Q1EVM Datasheet and I see than the input voltage range Vin is from 15V to 100V.

However, given your component choices, the LM5164 should start for input voltages as low as 6V.

It is mentionned that Vout follows Vin for Vin<12V. What about for input voltages between 12V and 15V ?

Why the datasheet says minimal input voltage is 15V and not 6V ?

Thank you by advance for your response,

Have a nice day,


  • The EVM is set for a 12Vout.  That means that the input voltage must be greater than 12Vin to regulate correctly.

    That is why the minimum input voltage is stated as 15Vin for this EVM.  With input voltages below 12Vout, the output 

    will try to follow the input voltage, less a small drop.  When the input voltage approaches the programmed 12Vout, plus a small headroom,

    the output will begin to regulate.  The headroom required will depend on the load current.  Somewhere between 12Vin and 15Vin the output will

    be in regulation, depending on the load current.  Beyond 15Vin the output will be regulated normally at 12Vout.

  • Thank you very much for your answer Frank De Stasi.

    For my application, I would like to use the LM5164 to power my 12V system from 12V, 24V or 80V batteries (cars, trucks, ...).

    I wonder then about the behaviour of the LM5164 when powered by 12V batteries (rather 12.6V minimum in reality for car batteries).

    I think I will buy an evaluation board and run some tests on it.

    Thank you again for your answer,

    Have a nice day.