PWM Deadtime Calculation for PWM

@ExperimeterUK

Forgot my last question.

As i told before that i have deadtime value as Input, from 0,5v to 3,25v. so from 2 to 24.
In which form i have to convert my deadtime inputed value?

when i write in Program deadtime(2). It takes easily but how can i give as Input. I alread convert this value into mV through ADC.
But i am bit confused how cani use this value to write deadtime?

while(1) 
{
       if ( AtoDdoneflg )     // A/D got a new sample ?
       {       									
	if(AMux_Flag == 0) //Deadtime Channel selected
	{														Deadtime_Ans1 =  ADC_DelSig_CountsTo_mVolts( Deadtime_Ans );  						              if ( ( Deadtime_Ans1 >
 Deadtime_Ans_Old  + 10 ) || ( Deadtime_Ans1 < Deadtime_Ans_Old - 10 ) )  
	            {   										
		Deadtime_Ans_Old = Deadtime_Ans1;
					
		// Enable PWM 
		PWM_1_WritePeriod( (300 );	       		
                                   PWM_1_WriteCompare1(141 ); 		
		PWM_1_WriteCompare1(141);
		PWM_1_WriteDeadTime(Deadtime_Ans1 );		
                            }				
	}	
	  AtoDdoneflg = 0;		// Reset A/D EOC flag		
}

When i run this program than PWM siognals jump irregularly.

Regards
Max

@ExperimenterUK
I make small table to observe Output with same period & compare value but changed Deadtime value.

Period = 300
Compare = 141

Deadtime-------ΔX------Duty
10------450ns--------43.5%
20------860ns--------40.2%
5--------250ns-------45.2%
2--------125ns-------46.2%
24--------1µs---------38.9%


i got ΔX right, which i needed so my clock is done (25MHz). But The Duty i Need always 47% What can i do for this

Max.otto

I'm not sure what you are asking.
With no dead time and maximum, equal phase lengths, each will be 50% of a cycle.
As you increase dead time the length of each phase will reduce,
that's what deadtime does.
I'm not sure PWM and the sort of phase length control you are doing
are the same thing.

while(1) 
{
       if ( AtoDdoneflg )     // A/D got a new sample ?
       {       									
	if(AMux_Flag == 0) //Deadtime Channel selected
	{														Deadtime_Ans1 =  ADC_DelSig_CountsTo_mVolts( Deadtime_Ans );  						              if ( ( Deadtime_Ans1 >
 Deadtime_Ans_Old  + 10 ) || ( Deadtime_Ans1 < Deadtime_Ans_Old - 10 ) )  
	            {   										
		Deadtime_Ans_Old = Deadtime_Ans1;
					
		// Enable PWM 
		PWM_1_WritePeriod( (300 );	       		
                                   PWM_1_WriteCompare1(141 ); 		
		PWM_1_WriteCompare1(141);
		PWM_1_WriteDeadTime(Deadtime_Ans1 );		
                            }				
	}	
	  AtoDdoneflg = 0;		// Reset A/D EOC flag		
}

When i run this program than PWM siognals jump irregularly.

Regards
Max

Max.otto

I count four opening braces '{' and only three closing braces '}'
Where is the missing brace ?

@ExperimenterUK

Only 1 question. I wrote in program deadtime(2). This 2 i have to give as analog Input from range 2 to 24. [bHow can i give Deadtime as Input? ][/b]

Regards
Max

Hello all,
i was bit confused of my requirment. But now i m sure abt it. I want to give deadtime as Input with vary Duty cycle.
I am working with PSoC.
Deadtime Input value is for 0,5v = 205ns & 3,25v = 1μs. (like 205ns, 250ns, 290ns, 330ns....1μs = 40ns Step). .

pls check the attached files.

Regards
Max