PWM Deadtime Calculation for PWM

Hii all,
i have Input Freq. 0,5v to 3,25v Output PWM have 2-256 cycles Clock freq. 24MHz.
I want to give
if Input = 0,5v then Deadtime = 2
& if Input = 0,5v then Deadtime = 24.

Is there any equation to do this?

Regards
Max

Do you mean if the input changes from 0.5 volts to 3.5 volts
the dead time changes from 2 to 24 ?

How is the dead time set in the controller ?

Which controller are you using ?

yes i mean this if the input changes from 0.5 volts to 3.5 volts
the dead time changes from 2 to 24 ?

I am using PSoC 5LP .

I take 1 PWM with 2 phases (reverse & Forward ). When i give deadtime as Input, then the Duty cycle for borh PWM phases will 49% of Period.

Regards
Max

yes i mean this if the input changes from 0.5 volts to 3.5 volts
the dead time changes from 2 to 24 ?

I take 1 PWM with 2 phases (reverse & Forward ).
When i give deadtime as Input, then the Duty cycle for borh
PWM phases will 49% of Period.

Is there any equation to do this ?

Max.otto

There is no standard equation as each case is different.

Start by getting a PWM running with equal on/off times.
Add a deadband.

Read the voltage using the ADC.
Use your own equation or a table to get what setting is
needed to create the wanted deadband.

Set the deadband in the DEADBAND_PERIOD bits
in the TMRx_CFG0 timer.

@ExperimenterUK,
how can i get PWM running with equal on/off times.??

Also check my new thread named " PWM signwave with 50ns freq. Step".

Regards
Max

Set duty cycle to 50% you will get equal on/off time.

How can i get PWM on-off time..?
pls check the attached design file & Project file.

Regards
Max

You set the on/off times here as 47%

float PWMcompare1 = 141.; // Desire that duty cycle = 47%, so PWMcompare = PWM_Period x .47 =~ 70
float PWMcompare2 = 141.; // Desire that duty cycle = 47%, so PWMcompare = PWM_Period x .47 =~ 70
float PWMdeadtime = 10;

If you just run Sys_Init(void),
what PWM output do you get ?

@ExperimenterUK
Thank u. I do it. Ohne Period it's not worked. So i thought u forgot to write it.

I take
float PWMperiod = 300.;
AS u told
float PWMcompare1 = 141.; // Desire that duty cycle = 47%, so PWMcompare = PWM_Period x .47 =~ 70
float PWMcompare2 = 141.; // Desire that duty cycle = 47%, so PWMcompare = PWM_Period x .47 =~ 70
float PWMdeadtime = 10;

The Output i got is
The PWM Step is as i Need 450ns (40ns Step).
But the Duty cycle is 43.5%

@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?

Regrads
Max