TL4242: External voltage applied to output

Thank you Sean.  Is this true even when there is no power applied to Vin?  Can I apply a voltage to Q when I = 0V?

Hi david,

     What do you mean the "when I=0V" it is floating or connetc to the ground? 

BR

Sean

It would be when one of the input power supplies is not present.  In my case that rail is quickly discharged down to about 2V when the input is removed and then slowly down to 0V.  So I think the answer to your question is that the input is connected to ground.  It certainly is not floating.

Hi David,

     I'm sorry that I don't think it can be power from the "Q" pin when "I" pin is connected to ground since there is a biode diode for the internal FET.

BR

Sean

Hi Sean,

The functional block diagram in section 7.2 makes it look like it is a PNP, rather than a FET.

 - Dave

Hi Dave,

    That is the simplifiere block diagram and it needs to test to confirm. Let me check with the internal team and reply to you later.

BR

Sean