TOP256YN noob question Posted by: Tsitsias on Fri, 06/25/2021 Hello all, I have a power supply from a projector that has a burnt TOP256YN AC/DC converter. I cannot find TOP256YN to replace it, can I use TOP259YN ? 댓글 Hi, TOP256YN has two frequency modes. If frequency pin connected to source, unit switches with 132 kHz frequency and if connected to control pin, unit switches with 66 KHz. TOP259YN has only one frequency mode of operation i.e 66 kHz. Please check your design before changing the device. If your design operates at 66 kHZ , use appropriate resistance on X pin to limit the current based on datasheet. TOP259YN is rated for higher power, so high current limit.