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All   >>  LED Lighting   >>   Mobile Applications   >>   Questions
 

We'd like to use your NCP1422 in our current design, as a boost converter to feed 1W LED in constant current (0.38A) mode from 2 AA NiMH batteries. To achieve it, \nwe plan add current measuring resistor ( from LED to GND) and op-amp, to tranlate voltage drop on the resistor to NCP1422 feedback voltage. From previous experience with similar LT and Maxim converters we know , that it may be necessary to add some compensation elements , to prevent output voltage oscillation.\nAny suggestion on components/values for this purpose?

It's a hysteretic part. Compensation is not required. The CFF cap is only for transient response in voltage regulation applications. For LED it only leads to jitter and noise injection.\nPlease see our application note at: http://www.onsemi.com/pub_link/Collateral/AND8171-D.PDF \nThank you. Answered by:
ON Semiconductor
2011-09-25 17:17:47.0