Fast switching mechanism

[Atif Hussain Shah]

I want to use a very fast Spdt Rf switch Masw20000 and want to control it through Fpga.it has two control signal inputs A and B. The control signals required for this switch are 0V and -5V for switching of one state and -5v and 0v for switching to other state.
The problem is that i cannot provide -5v from fpga.
One solution is to use an inverter but its responce is slow.
I want to genarate control signals 0v and -5v within 1ns.
If Any idea or solution

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--- Updated Jul 11, 2021 ---

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[barry]

what do you mean ‘the response of the inverter is slow?’. Just switch the inverter output. you could use an analog switch, FET, etc.

 

[martinnl]

The masw2000 datasheet specifies a Ton and Toff of 3 ns from 50% of the control signal to 10 or 90% of RF. This means, I assume, it takes 6 ns to switch over even with an infinitely fast driver.

Also, when you say the inverter is to slow and you want it to output a -5 V signal from a FPGA something sounds strange. How is your connection? What inverter are you using? What are the supplies?

 

[Easy peasy]

he wants to some how generate a fast 0 to -5V signal, from his FPGA pin going either 0 - 5V, or 5V - 0v

 

[barry]

The masw2000 datasheet specifies a Ton and Toff of 3 ns from 50% of the control signal to 10 or 90% of RF. This means, I assume, it takes 6 ns to switch over even with an infinitely fast driver.

Also, when you say the inverter is to slow and you want it to output a -5 V signal from a FPGA something sounds strange. How is your connection? What inverter are you using? What are the supplies?

it takes 3ns to turn on or off. Why are you adding the two times together?

 

[Atif Hussain Shah]

The masw2000 datasheet specifies a Ton and Toff of 3 ns from 50% of the control signal to 10 or 90% of RF. This means, I assume, it takes 6 ns to switch over even with an infinitely fast driver.

Also, when you say the inverter is to slow and you want it to output a -5 V signal from a FPGA something sounds strange. How is your connection? What inverter are you using? What are the supplies?

Thanks for reply
I simply want to generate 0V and -5V within 1 ns. The signals from FPGA output is either 0v or +5V. So 0V is available but i need to generate -5V. What will be the fastest method to generate -5V?

 

[KlausST]

Hi
The fastest I can think of is "capacitive coupled".
5V DC across the capacitor gives
FPGA --> SWITCH
0V --> -5V
5V --> 0V

Klaus

 

[barry]

Thanks for reply
I simply want to generate 0V and -5V within 1 ns. The signals from FPGA output is either 0v or +5V. So 0V is available but i need to generate -5V. What will be the fastest method to generate -5V?

I still don’t understand why you’re hung up on “generating -5V in 1nS”. Just use a regulator to generate -5V, and put a switch on the output. But that 1nS requirement is pretty tough. Do you REALLY need that fast a rise time? The output of the FPGA certainly isn’t going to change that fast.

 

[BradtheRad]

It sounds as though you want to make a positive signal switch a negative supply on and off to a load. It can be done by a transistor if you adjust the bias carefully.
This method can be quick because only one device is used.

 

[martinnl]

My reasoning was that it takes 3 ns to turn off and 3 ns to turn on and you don't want them to overlap. But if that is acceptable it would take 3 ns.