high current for pulsed nanosecond

Pooya Ba's picture

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Joined: Feb 25, 2021

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high current for pulsed nanosecond
February 25, 2021 - 10:33pm

Hello
  I am am trying to run a nanosecond pulser circuit. This circuit is controlled by a flap. Therefore, a nanosecond pulse is generated and increased to 8 volts by an amplified transistor. Then, the transistor is connected to the MOSFET gate.
I designed this circuit to have a strong single pulse of light. Also operating-speed of the circuit is 100 nanoseconds.
My problem is with the Hebrew current through the ledge which a very little current passes through. But I want about 10 amps to pass through this led current.
Please let me know what is the problem with my circuit.

a.JPG

Sourav Gupta's picture

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Joined: Feb 12, 2018

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ThisThere are few problems in the circuits. First of all 1 nanosecond pulses is equivalent to 1 GHz. This is a very high frequency. Next thing is 100nS turn on time of IRF540 is very fast and to work on this region you need solid PCB constructions. How you testing this circuit?

Pooya Ba's picture

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.The circuit is closed on a two-layer PCB and can now operate at 100 nanoseconds
.My problem is the led current, which is very low and I want to increase this current

Sourav Gupta's picture

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What is the partnumber of the LED?

Pooya Ba's picture

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VLMTG1400

Sourav Gupta's picture

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Well the LED is ok. Do not have problem. I question about the MOSFET driver. In such high frequency how you calculating the parasitic inductance of the whole circuit? The MOSFET has high gate capacitance around 2nF. In such low time, this gate capacitance will pull very high amount of current for the input.

 

You could use dedicated gate driver and change the MOSFET with a low input capcitance. I think this will solve a lot of problems.