I'm using Viper37LD in my project with the following features:
Vin: 85-270VAC
Out1: 12V-1.5A
Out2: 15V 0.125mA
I used eDesignSuite to calculate component values.
I have some boards mounted and I have the following situations:
1- The source does not regulate the 12V and 15V. These voltages pulse with or without connected load.
2- When inserting a capacitor in parallel with Rlim (33pF), the source will correctly regulate the voltages of 12V and 15V, with and without load, however, my Vin range is not obeyed. The regulation starts around 60VAC and stops regulating around 170VAC.
3- The voltages of 12V and 15V are not switched off with 270VAC. If I increase the value of the capacitor in parallel with Rlim, two situations occur: shut down before reaching Vin = 270VAC or does not turn off when arriving at Vin = 270VAC.
I would like to know why my project only works by inserting a capacitor in parallel with RLim and how can I get my range of Vin obeyed. Could it be a layout problem?
