Why Latched-Comparator are not preferred in PWM applications

[chanchg]

Hello Everybody,

Why Latched-Comparator is not preferred in PWM block of a Switching Regulator?
In other words, what is the advantage of OPAMP Comparator and Latch Comparator over each other?

Regards,

 

[huojinsi]

Re: Why Latched-Comparator are not preferred in PWM applicat

The function of OPAMP amplify error signal that feedback from out.
The function of PWM comparator generate PWM wave.
I cann't understand your Latch Comparator ,does it have Latch Comparator in the Switching Regulator? RS latch is included in the Switching Regulator.

 

[ambreesh]

Re: Why Latched-Comparator are not preferred in PWM applicat

Are u talking of comparator with internal hystersis as latched comparator

 

[kart339]

Re: Why Latched-Comparator are not preferred in PWM applicat

Actually, I am using a latched comparator in my switching reg controller now. It has some very good points in its favor like a 30ns response time. But the main disadv I have noticed so far is its resolution/accuracy. It's not its strong point! More info on latched comparator: check following IEEE paper,

"Design techniques for high speed high resolution comparators" by Behzad Razavi and Bruce Wooley in JSSC Vol 27, No 12 Dec 1992.

Hope this helps!
Kart

 

[ambreesh]

Re: Why Latched-Comparator are not preferred in PWM applicat

Are u guys intrested in Razavis PhD thesis as that paper is but a fraction of that thesis