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Operating in regulated configuration with Vin < set Vout

Category: Hardware
Product Number: LT1054

Hello,

I am planning to use the LT1054 as a regulated voltage inverter in a design where there is the possibility that the input voltage level will drop below the set output level during some operating conditions.  

If that occurs while there are feedback resistors in place, will the part operate the same as the unregulated configuration where Vout = Vin - (internal switch losses)?  

Is there any change of damage to the part, or the output inadvertently shutting down during this operating mode?  The design can tolerate if the output voltage drops to track the input with losses as long as this will not cause any damage or functional issues with the LT1054.  

Thank you,

Nick

  • If the input droops below -(VIN - IRlosses) then the LT1054 will start operating open loop. If the input droops below the VREF voltage of 2.5V then the part might possibly turn off. With voltages less then 3.5V the switches will get more lossy and the part will not be able to output as much current. 

    No damage should occur to the part operating in dropout.