Recently, I have designed a power supply system using ADP5050 as a power module for Altera FPGA system.
After fabrication, for a certain reason I couldn't figure out, the output voltages differ from the voltage as they should be. For example, the 3.3V output is measured by about 3.02V, and so on. After thorough investigation why this happens, I have figured out the internal reference voltage seems to be different from 0.8V (Ch1~Ch4). For say, the internal reference voltage is measured by 0.74 V approximately. (at the pin FB1, FB2, FB3, FB4)
I don't know if this 0.74V is within the normal range of ADP5050. The datasheet does not say about the internal voltage range. I am OK with this deviation because I can replace the top resistor and bottom resistor with other resistors to get the correct output voltage, unless the output voltage goes unstable.
Is there anybody to tell the internal reference voltage 0.74V is normal?