Any Active Low MOSFET Switches?

[mansoor7777]

I need a high side switch similar to FDC6323L but which turns on when ON/OFF is low (0 V) and stays off when ON/OFF is high (or Open). I searched for them on digikey but could not find them (there are several thousands of them and the few I checked were all like FDC6323L).
Does anyone know of one such switch? I would like to avoid general purpose MOSFETs and stick with switches that are meant for that purpose.

Best Regards

 

[dknguyen]

Just use an inverter.

 

[user_88]

If you can't find exactly what you want, take look at this,
**broken link removed**

... a high side n-channel mosfet driver .... you would have to supply the external mosfet though.

I didn't completely understand the graphical icon for the external mosfet in the maxim MAX1614 datasheet...
The chip description implies that it is an n channel enhanced mosfet, but the drawing doesn't exactly comply with standard depiction of enhanced n-channel mosfets ....

 

[Analog]

I need a high side switch similar to FDC6323L but which turns on when ON/OFF is low (0 V) and stays off when ON/OFF is high (or Open). I searched for them on digikey but could not find them (there are several thousands of them and the few I checked were all like FDC6323L).
Does anyone know of one such switch? I would like to avoid general purpose MOSFETs and stick with switches that are meant for that purpose.

Best Regards

Why not use a depletion mode MOSFET? They are normally on when their gates are at 0V.

 

[mansoor7777]

Thank you all for your comments. I just ended up using an inverter (no way I could easily avoid it).

 

[duffy]

Aww, just use a P-channel mosfet. Turns on when you bring it to ground, goes off when you send it high (positive rail). Just like you want.

I would like to avoid general purpose MOSFETs and stick with switches that are meant for that purpose.

That purpose is what a P-channel mosfet is meant for.

 

[dknguyen]

I think he doesn't want to have to deal with the gate drive, which he may still have to do with a P-channel under some circumstances (like the primary voltage exceeding the gate voltage).

 

[duffy]

I think he needs to splash a shot of Jack Daniels on the solder sponge and attack that son of a ***** with a soldering iron. Stop looking for some wussy chips and straight hardwire P-channel MOSFETS into it. Cuss a bit, pound your fist on the bench and MAKE make those damn electrons go the right way round the circuit. This is how a real man deals with high-side driver issues.