I am using USB2244 chip. I detected the following problem: There is 1.8V observed at pin 13 and 34 which should normally be the case (1µF capacitors are connected as according to the data sheet) , USB is not detected . I changed the pin13 capacitor (1uf to 1nf) and pin34 (1uf)., USB is detected. what is the problem? why changed the pin13 capacitor USB detected? its right method?

 

Why did you think to try changing the \( \mathsf{V_{DD}18} \) capacitor?

Do the 1µF capacitors you are using have the <0.1Ω ESR called for by the datasheet? Did you try a different 1µF capacitor before trying the 1nF cap?