iP7302

iP7302 TRANSITION-MODE SINGLE STAGE PFC LED POWER SUPPLY 1. Description 2. Features The iP7302 operates on fly-back circuit after rectifier diode, so the waveform of input current follows that of input voltage. It is a peak current mode fly-back PFC controller, with valley turn-on /Quasi Resonant mode (QR), so very high efficiency is easily achieved. iP7302 is different from iP7300 in the connections of inputs of error amplifier between pin1 and pin2. The Pin1 is connected to positive input and pull up 50KΩ resistor to internal supply of 5V. The negative input is connected to output to form unity gain buffer. Pin2 is non connected. This modification is specially made to suit single stage LED power supply which requires PFC. The structure of single stage LED power supply with PFC offers several advantages: high PF, no need of bulk electrolytic capacitor, output isolates from line input, reasonable size and cost. The disadvantage is that the output contains 120/100Hz ripple. But wit...