Constant current led driver using uc3845

[grittinjames]

Hi,
I tried to make a constant current LED driver using UC3845 to which vtg feedback is given as the drop accross sense resistor. Even though it is working the loop seems not stable. i am seeing a ringing which mayrequired slope compensation.
Any body plse help me how to solve this

 

[Tahmid]

If duty cycle goes above 50%, you need to use slope compensation, such as this:

Added after 1 minutes:

Check the datasheet for details.
Hope it helped.
Tahmid.

 

[grittinjames]

But i am operating below 50%, But as i mentioned it is as constant current,
Voltage feedback is taken from v drop of Isense resistor