Hi,
my pcb have 2 power connectors. One with an input voltage from 35VDC and the other with an input voltage from 5VDC. It's safe that only one of these are used at the same time. The 35VDC voltage used the switching regulator LM2674-5.0 to convert the voltage to 5VDC. My question is:
Do i need a protection diode from the output to the input pin at the LM2674-5.0 like you make it at a linear regualtor? Or is there some other protection necessary?
Greetings
Lars
Hi Lars,
Apologies for the late response.
Could you please attach a schematic/diagram so we can see your configuration? You mentioned that you have 2 input voltages (35VDC and 5VDC) but you also have a regulator from 35VDC and output 5VDC? Is your configuration something like the image below? Do you want to implement an OR function for the two 5V rails?
Regards,
Denislav
Hi Denislav,
this is the schematic from the regulator:
It's possible to connect 24VAC or 5VDC (Micro-USB) to the circuit. The MOSFET T220 and T221 de-energize the 5V-USB when the main supply current is connected. When i only connect the 5V-USB then i have a 5V at the output from ic 220. Is this a probblem for the voltage regulator (ic220) when the output voltage is 5V higher than the input voltage?
Regards,
Lars
