Class D circuit implementation

crutschow

Joined Mar 14, 2008
34,280
Are we talking about the signal level?
I though you were talking about the V1 bus voltage.

You did not read the data sheet (snip below), which clearly shows that Vdd must be 3.3V if you have 3.3V logic signals.
You have it connected to V1, 15V.
Please read the complete data sheet before you come back with more questions. :rolleyes:

upload_2017-11-2_20-21-46.png
 

Thread Starter

Hassan Wahaj Malik

Joined Oct 15, 2017
45
Are we talking about the signal level?
I though you were talking about the V1 bus voltage.

You did not read the data sheet (snip below), which clearly shows that Vdd must be 3.3V if you have 3.3V logic signals.
You have it connected to V1, 15V.
Please read the complete data sheet before you come back with more questions. :rolleyes:

View attachment 138561
My circuit is shorting out as soon as i connect the low input to the gate driver.
Any idea why that might be?
Thanks
 

dendad

Joined Feb 20, 2016
4,451
How have you added the diode?
Is it like this..
PWM-Amp.jpg
With the PWM signal running, there will be about 15V across C2, or from the top of C2 to the ground, about 30V.
It may be an idea to use high speed diodes and not the 1N4001 variety. You will probably get away with 1N4148 diodes.
 

Thread Starter

Hassan Wahaj Malik

Joined Oct 15, 2017
45
How have you added the diode?
Is it like this..
View attachment 139086
With the PWM signal running, there will be about 15V across C2, or from the top of C2 to the ground, about 30V.
It may be an idea to use high speed diodes and not the 1N4001 variety. You will probably get away with 1N4148 diodes.
I used MUR120 on the circuit itself. That one is a high speed diode aswell. I’ll try to use 1N4148
 

dendad

Joined Feb 20, 2016
4,451
I used MUR120 on the circuit itself. That one is a high speed diode aswell. I’ll try to use 1N4148
If you have the MUR120, that is ok. Don't worry changing it, The one you have is probably better. At least it has higher current rating.
It is just the circuit diagram had low speed ones.
 

dendad

Joined Feb 20, 2016
4,451
It may help if you put the full circuit up for us to see.
For instance, you have a NOT gate there. What is it and what are all the pin connections?
A bit like your circuit shows 1N4001G diodes but you are using MUR120 diodes.
What is your 15V supply and do you have any power supply bypassing capacitors other than the C1?
There may well be other problems that are not shown.
 
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