Part Number: UCC28740 Other Parts Discussed in Thread: PMP9638 , LM341 , TL431 Tool/software: Hi,
I need help with the UCC28740 design based on the PMP9638 reference design.
1) Why is it not switching? The schematic is attached. My Auxiliary winding is…
Part Number: UCC28740
Hi team,
My customer is using UCC28740, and they meet issues during low Vin start up.
During low Vin start up test/72Vac Vin, due to the suddenly load change from 0A~1.6A, UCC28740 VCC will be pull down below UVLO making device…
Part Number: PMP41009 Tool/software: Hi,
I made a flyback power supply with reference to PMP41009. But the switching frequency is not stable when a constant load is added. So what is the possible cause? What are the adjustments?
Thank you
Part Number: UCC28740-Q1 Other Parts Discussed in Thread: UCC28740 Tool/software: HI team,
A quick question on UCC28740, the Vin is 800V/400V DC voltage, output is 10V/2mA very light load, what's the input current for 400V and 800V respectively?
…
Part Number: UCC28740 Hi,
Situation ・AC200V is rectified to DC282V, which is used as the input power source. ・There are variations in the time from power-on to 5V output. The startup time varies from 100ms to 400ms. ・Differences of startup time occur in the…
Part Number: UCC28740 Hi, I'm designing a flyback converter for an E-metering application and facing EMI issues. I doubt the bobbin geometry of transformer. Will EMI be impacted based on the selection of horizontal or vertical bobbin? I'm currently using…
Hi Shilin,
Sorry for the late reply. The clamp voltage VC 414V is tested at the peak maximum peak pulse Current 1.5A, and it is from 256V ~ 315V when the test current is 1mA, the current will not exceed 1mA for PMP41009, so the maximum voltage at HV pin…