Information request for L6566B Vref voltage reference. A 24 VDC, 10 A AC/DC converter design has been done using the eDesignSuite on the ST website. In this design, L6566B controller has been used. After production of the prototype converter, we tested the converter using loads 4-5 amps. There was no problem at first. But later, we encountered some problems. The output voltage is increasing gradually starting from 8VDC to 24VDC with no load. But when we connected a load, the output voltage drops to 2-6 VDC level for 20mA load (0 VDC for loads more than 2 amps) and then tries to restart. We have seen that there should be an accurate voltage reference (5V ± 2%) at the Vref pin (10) of the L6566B in accordance with the datasheet, Table 1 and Table 4. We have checked the pin 10 of the L6566B and there was no 5V even though there was no load at the output. No matter what we did, we couldn't get it solved. We
