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Negative output Voltage

Category: Hardware
Product Number: LTC1624


I found a component that may be suitable for my application the LTC1624 (please see the DS in this attached). I don't understand very well how it works this electronic assembly :

Is it possible to delete M2/M3 and R3 to have something simpler. I have only +12V (comes from the battery voltage) and I need -5V with 1A to the ouput. Thank you for your helps.


Yann DOPDF   

You can use this schematic and adjust accordingly to satisfy your specification.

  • FormerMember
    0 FormerMember in reply to 206_RC

    You would need to find and import the spice model for the component.

  • After working under LTpowerCAD I lost all the schematics of the simulation. Can I work with LTspice (that I know a little better). ? I think it's the same unless I am mistaken.

    Under Mouser I can see 2 models for this component, I think  I must take the second model  Spice2 Model for 'MBRS340T3' and not PSpice I suppose ? 

    Do you have links or information to import components under LTspice for simulation ? Thank you for your feedback


  • Thank you this diagram will be very useful to me but I will need -5V and not +5V and do you know the method to ajust the current to +1A instead of +2A like your schematic ?

    Thank you for your helps


  • Hi,

    After drawing the circuit I don't get -5V but -6V. 


     Something is wrong but I don't know where. But after the DS normally I'll have -5V with a supply +12V 


    I just removed the following components : M3/M2/R3 and Shutdown. Do you have a idea where is my mistake ? Please see in this attached my simulation. 


  • Thank you Jhun,

    But my goal is to find a to find a circuit with a negative voltage at the output (-5V). Do you how  I guess I have to calculate the component values ​​to get the -5V. I found this electronic assembly but it is enough that I adapt a little to find the -5V right ?


    Thank you for your helps


  • FormerMember
    0 FormerMember in reply to 206_RC

    That is a negative output.

    In the schematic,

    The referenced ground is the VNEG output.

    The circuit I sent is an alternative as to how to generate a negative output from a buck controller in the simulation.

  • The referenced ground is the VNEG output.

    Sorry but I can't see the VNEG output in your schematic. Where it's (sorry I'm a beginner under LTspice).

    Where must I take my probe to see the negative voltage ?