PLL phase shifter

Thread Starter

ako

Joined Mar 14, 2009
10
Hi All,Is it possbible to phase shift by 180% a 150-250kHz variable frequency PWM signal with a duty cycle of 40-60%using a single supply voltage LM565 PLL?Complete newbie badly needs help on this one. Thanks..
 

beenthere

Joined Apr 20, 2004
15,808
Wouldn't it be easier to run the signal through an inverter? Or change the control? A 50% duty cycle remains 50%, 60% becomes 40%, and so on.
 

Thread Starter

ako

Joined Mar 14, 2009
10
I need the signal for interleaving purposes which is variable frequency, and a change in duty cycle wouldn't be right anymore.
 

beenthere

Joined Apr 20, 2004
15,808
Draw up a 60% duty cycle PWM signal on graph paper. Do a 180 deg. phase shift on it. See if that hasn't made it a 40% duty cycle signal.
 

Thread Starter

ako

Joined Mar 14, 2009
10
I think some kind of signal delay is what I'm looking for right now. Does phase shift always mean a change in duty cycle (assuming that D is not 50%)? Really confused about this topic.
 

beenthere

Joined Apr 20, 2004
15,808
A 180 deg phase shift simply inverts the signal. Signal delay is different. What kind of delay are you after?
 

hgmjr

Joined Jan 28, 2005
9,029
Hi All,Is it possbible to phase shift by 180% a 150-250kHz variable frequency PWM signal with a duty cycle of 40-60%using a single supply voltage LM565 PLL?Complete newbie badly needs help on this one. Thanks..
You say 180%. Do you really mean 180 degrees?

hgmjr
 

Thread Starter

ako

Joined Mar 14, 2009
10
180 degrees. Sorry.. The kind of delay that is implemented in interleaving PWM IC's in which the duty cycle is preserved. Only that in my case its variable frequency. Can a PLL do the job?
 
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