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100-200ns comparator needed for DIY Constant off time controller

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We are doing a 230VAC offline, 150W, Power Factor corrected, single stage LED driver.

We need constant off time control. However, there are no OffTheShelf control chips available for this purpose. Therefore , we have to make our own as in the attached schematic.

As you can see, the DIY constant off time controller unfortunately consists of three separate IC’s and a signal FET….As you can see, there are also a number of resistors involved there. There are fast, high rise time signals within the bounds of the controller, and shielding this lot of components from noise will be a challenge.

As such, we need to use hysteresis with the PWM comparator. The LT1713 comparator gives a very convenient Q! signal which is ideal for giving hysteresis. However, the LT1713 comparator is way too fast for our purpose, (it’s a 7ns comparator). We need a 100-200ns comparator instead, to make noise free operation easier to achieve. However, there are no OffTheShelf comparators which have the Q and Q! outputs that the LT1713 does. Can you confirm this? Do you know of a 100-200ns comparator with Q and Q! outputs?

Schematic and LTspice sim attached.



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Just add a little RC delay at the input if you need to slow it down.
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