Hello , I have tuned the following topology to do level shifting from ttl to -2 to -6 pulse.
This topology is good because I can tune the output pulse.
Three questions:
1. input rise time and fall time is 20ns but the output fall time is about 70ns is there a way to make it faster?
2.maybe there is a better topology?
3.This level shifter goes straight into VGHV1A250F which has 100pF gate capacitance.
when I plugges 100pF at the load I got oscilations as shown below.
maybe I represented the gate of the amplifier in a wrong way?
4.what could I do deliver that fast pulse and not to oscilate?
Thanks.
https://cdn.macom.com/datasheets/CGHV1A250F.pdf

 

You are trying to amplify pulses with a high power GaN Amplifier 50 V, 250 W, made for operation at 8.8 - 9.6 GHz!
This is a CGHV1A250F amplifier "Suitable for Linear & Saturated Applications." It is not characterized as a pulse amplifier.
In addition, the power supply connections may not be adequate to supply the power to drive the fast rise times.

 

Hello , I have tuned the following topology to do level shifting from ttl to -2 to -6 pulse.
This topology is good because I can tune the output pulse.
Three questions:
1. input rise time and fall time is 20ns but the output fall time is about 70ns is there a way to make it faster?
2.maybe there is a better topology?
3.This level shifter goes straight into VGHV1A250F which has 100pF gate capacitance.
when I plugges 100pF at the load I got oscilations as shown below.
maybe I represented the gate of the amplifier in a wrong way?
4.what could I do deliver that fast pulse and not to oscilate?
Thanks.
https://cdn.macom.com/datasheets/CGHV1A250F.pdf
View attachment 365995
View attachment 365997

What you must do is provide an adequate explanation of the purposeof having that outputvoltage spread.
If thatsignal was originally standard TTL levels, the TS must have some goal tgatthey must share.

 

Hello ,how can I make my circuit faster rise and fall times?
Thanks.

 

The rise and fall time of a voltage is controlled by the current sourceing/sinking capability of the power source. That is one of the main reasons that capacitors are connected across the power source at the load. That is a seldom adequately emphasised part of circuit design lessons.

 

In addition, any amplifier must also transfer power to the following device, whatever it is. for best power transfer the impedances should match. So weneed to know the load impedance.
My guess is that with that output voltage it is a bipolar power transistor.