Other Parts Discussed in Thread: LMR16020, LM46002, TPS2372, , LMR16030
Ive inherited the attached design from a previous design and im having issues with its operation.
I wonder whether somebody could take a look and comment on the design and offer guidance on how to make it better, more robust or a completely offer a completely different design.
It is meant to take an input of 48VDC (typ) but could see 44 to 60VDC input. The maximum input current available is 600mA. Using the switched resistors, it is meant to supply an output voltage across a range of 12 to 42VDC.
If i set the output to 42V and apply 48VDC with loads of 100 or 200mA, the circuit starts up. Any higher current, 300, 400 or 500mA and it doesnt start up and provide an output voltage. Yet if i start with a load of 100mA and slowly increase in 100mA steps i get a voltage all the way to 500mA.
I see a similar issue if i set the output voltage to 12V, i dont get outputs much after a load of 1400mA
My thoughts are that the design should have been undertaken to achieve 12V at 2A output, 60VDC input. When this was confirmed as working, the feedback resistors could be changed to set the different output voltages. I would expect the efficiencies would drop as you moved further from the 12V output which the components were selected for. Is this a correct assumption?