Other Parts Discussed in Thread: UCC28810, TPS40211
Hello, first please forgive me to ask this novice question because I'm very much a rookie at power supply designs. 2nd please understand that I tried to tag the reference design but the message board told me it does not recognize it so I'm posting the link to the reference design in the post itself, the reference design is:
I'm not sure if the link can be properly displayed because it got wrapped automatically.
Anyway, I'm trying to tune down the output voltage from 50 volts minimum to 36 volts minimum and let it work permanently at that state, also I'm trying to modify the current from 500ma MAX to 2 A MAX or at least 1.5 A.
Note that I do not know if this will work so please speak your mind.
First of all my thoughts on the output voltage:
I looked up the datasheet but to be honest I couldn't find the part dealing with changing output voltage. I understand that you can either modify the turns ratio N of transformers or the duty cycle D. I'm thinking since the input is a variable between 85~305, there must be a pair of resistors or resistor-capasitor combination somewhere that dictates certain pin or pins of the ucc28811 chip (ucc28811 and ucc28810 should be interchangeble I assume? with minor differences?) to adjust the duty cycle (the on time off time of the GDRV pin output signal) (since the turns ratio is fixed) to produce the desired output voltage. So where are such resistor(s) capacitor(s)? Please help me find them so I can tune the output voltage from originally 50 V to 36V, again, I do not know if this is at all possible.
Then let's move on to output current:
To my limited understanding, the maximum output current is limited by the core of the secondary side of the transformer, limiting factors include for example the heat dissipation. So what I'm trying to ask is, since the original design limited the output current at 500mA max, can I change that to 2A or at least 1.5A by replacing the transformer with a more "robust" one? I assume the cost would go up.
Thanks for any advice!