12 v to 5 v using RT7272 chip, chip work 1 ~ 2 seconds to protect, what reason be?
Circuit principle diagram as shown in figure 1, the circuit board material object as shown in figure 2, RT7272 manual recommended circuit as shown in figure 3



Circuit board after the 12 v power supply, work 1 seconds to protect, and insurance FU1 fever, capacitor C1 and C2 is damaged, remove the C1 and C2, circuit board electricity work protection again after 30 seconds, RT7272 FU1 and very hot, could you tell me where is it?

CodePudding user response:

This is a not easy to find errors,

Tantalum capacitor welding inside out, is at the end of the positive signs, C1 and C2, C6, C7, in turn, if the capacitor is damaged, change new capacitor,

This is a lot of people don't know the pitfalls, thought is negative signs,

CodePudding user response:

Thank you, finally found the problem!

CodePudding user response:

If the voltage is higher, is the tantalum capacitor will explode,