High Voltage switching in a few microseconds

[misha82]

High Voltage Switching

hi
i have a problem.i have to switch hosh voltage in range 500v- 1500v. n have to do it in a few microsecond. can any one give me a solution for this. the used device should be very small in size like an IC or little bigger.
pls solve my problem
regards

 

[flatulent]

Re: High Voltage Switching

Several companies make transistors that can handle several kV. Your speed requirements rule out mechanical relays and four layer semiconductors.

One thing to keep in mind is that most passive parts are not rated for these high voltages. You have to use specially designed types.

 

[sinatra]

Re: High Voltage Switching

It is still possible to use solid-state single devices to switch in this high voltage levels.

Bipolar transistor:BU508. If you want to use a bipolar transistor the traditional BU508 can do this job. It will be switching in the microseconds range.

Mosfet: 2SK3748. MOsfets will be able to handle this high voltage up to 1500V. But the Rdson is a little bit high. So they will not be able to handle too high current. Tenths of nanoseconds switching time are acheavable.

IGBT: The y will be able to handle higher currents then mosfets but on the other hand it will be more difficult to go to voltages higher than 1200V. tenths to hunderths nanoseconds swtching times.

Due to the higher voltages involved those devices are a little big. Packages like to247 are to be expected.

You may also put devices in series, 2 or more, to increase reliability being far from the breakdown.....

It seems that you are looking for something small. I'm affraid it will not be very easy to find for such high voltages. If you can accept very slow switching times arround 100ths os miliseconds! Than a combination LDR-lamp could do the job...... You would need anyway to find an LDR that could withstand such high voltages....

S.

 

[hanifah]

Re: High Voltage Switching

Hi

If anybody know what is the suitable driver for 2SK3748 that apply in the full bridge inverter. Thank you for information and suggestion

 

[rfzheng]

High Voltage Switching

the voltage is too high

 

[FvM]

Re: High Voltage Switching

the voltage is too high

No, it isn't. You can use driver solutions that are applicable for high voltage IGBT, e.g. driver modules from Eupec or Concept, or
any own design with appropriate voltage isolation. You can't use simple level shifting IC drivers, also optically isolated drivers
have possibly an insufficient withstand voltage.

 

[hanifah]

Re: High Voltage Switching

Thanks for the input

Actually, I need the driver and device with high voltage up to 3KV (1.5KV-1.5KV Full Bridge) and switching frequency up to 1microsecond. When I search Eupec, the IGBT can't achieve high switching frequency as I needed.

I try to use any own design with appropriate voltage isolation but it look like very complicated. Do you have any good suggestion to solve this problem.

Thank for the infromation and reply.

 

[rfzheng]

the switch time is two fast, you know, several thousand votlage sweep need more time to set up.

 

[FvM]

the switch time is two fast, you know

I guess, you don't know, because the application description has been simply unclear. As the last post is talking about µs switching frequency in contrast to switching time as originally requested, which question you're answering?

Below µs switching times can be achieved with IGBTs, µs cycle time surely can't.