[SOLVED] Switching between two Negative voltages

[ahsoopk]

Hi all,

I need to source a SPDT that can switch between two negative voltages (-5V and -2V), this will be used to switch the gate voltages of a GaN FET. So far what i have found online they only switch positive voltage, if anyone has such a switch or know any method to do this, please help.

Many thanks in advance.

 

[FvM]

Any analog switch with bipolar voltage range (usually having dual supply) can do this from the scratch, also an unipolar switch with negative supply and level shifter for the control input. Many other possible solutions depending on the details requirements, e.g. intended switching speed.

 

[ahsoopk]

Any analog switch with bipolar voltage range (usually having dual supply) can do this from the scratch, also an unipolar switch with negative supply and level shifter for the control input. Many other possible solutions depending on the details requirements, e.g. intended switching speed.

switching speed has to be less than 100ns and is there any COTS part available for this job that you might have used or can suggest. or any circuit.

 

[FvM]

With a gate capacitance specification, the 100 ns can be translated to switch resistance and current rating.

 

[ahsoopk]

With a gate capacitance specification, the 100 ns can be translated to switch resistance and current rating.

Thanks for the reply but makes no sense to me as I am amateur in the field, trying to find my feet. some circuit example or bit more elaborated help will be deeply appreciated.

Many thanks in advance

 

[BradtheRad]

To handle negative voltage supplies and negative signals, and have them referenced to 0V ground, it may be easier to think in terms of PNP or P-mosfet devices. Their operation is a mirror counterpart to N devices. In the same way it seems natural to associate N devices with positive supplies and positive signals. The situation is reversed with P devices.