LR2257 - AC/DC Current Mode PWM
Pin Symbol Pin Description 1 FB Feedback input 2,3 NC Test Pin * 4 VDD Power Supply 5,6 SW Power Transistor output 7,8 GND Ground *Note: Test2 should connect to Test3 while in application 2/9 + - LO HI Working Principle HI HV DC LO 1M GND SW LR2257 12 3 4 PC817A 12 56 7 8
LR2257 Features
* of over current and over voltage protection mechanisms Delivering up to 3W yet consumes, the typical application of the device will include: z Battery Charger, such as handset phone z Power Adapter z Offline Power Generator z Etc. ¾ Lowest Total Cost Solution ¾ Low Power for Green Environments Prot
