CLASS D Amplifier Circuit Question

Thread Starter

Lucas Castelan Prado

Joined May 12, 2016
4
Hello everyone

I`ve been searching about class D amplifies.

What I know so far is that a class d amplifier is a switching amplifier.

There are three steps in creating a classe d amplifier.

1 - create PWM from signal.

2 - amplify output from PWM with switching transistors

3 - use a low pass filter.

The problem is that in step two, I have 2 transistors from Vcc to ground.
It seems that I need a delay circuit to prevent my circuit from having a short circuit from Vcc to ground(when both transistors would be conducting at the same time).
But i can't find a circuit like that to help me
Can anyone help me please?

This is the block diagram
https://upload.wikimedia.org/wikipedia/commons/4/4c/Pwm_amp.svg
 

wayneh

Joined Sep 9, 2010
16,397
Do you want to build one or just get one? You can buy them very inexpensively - cheaper than you can make one.

Have you searched for schematics for Class D amplifiers? You'll find hundreds. And yes, they all have to solve the "shoot through" problem.
 

Thread Starter

Lucas Castelan Prado

Joined May 12, 2016
4
Do you want to build one or just get one? You can buy them very inexpensively - cheaper than you can make one.

Have you searched for schematics for Class D amplifiers? You'll find hundreds. And yes, they all have to solve the "shoot through" problem.
i want to build one on ltspice
 

ronv

Joined Nov 12, 2008
3,770
Hello everyone

I`ve been searching about class D amplifies.

What I know so far is that a class d amplifier is a switching amplifier.

There are three steps in creating a classe d amplifier.

1 - create PWM from signal.

2 - amplify output from PWM with switching transistors

3 - use a low pass filter.

The problem is that in step two, I have 2 transistors from Vcc to ground.
It seems that I need a delay circuit to prevent my circuit from having a short circuit from Vcc to ground(when both transistors would be conducting at the same time).
But i can't find a circuit like that to help me
Can anyone help me please?

This is the block diagram
https://upload.wikimedia.org/wikipedia/commons/4/4c/Pwm_amp.svg
IR makes several with built in dead time. I have models for some of them.
http://www.irf.com/product-info/datasheets/data/ir2184.pdf
 
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