SMD SOT23-5 Please help me identify component

[radcza]

HI.
Can I please for help in identifying the following SMD component? Package is SOT23-5. Marking is bPCGD . Probably is voltage detector or regulator but I dont know the ecaxt parameters. It is a component of mainboard IP camera YI YHS3017.
I add photos of the mainboard. Pinuot 3 is connected to a nearby coil, pinout 2 is ground, pinout 4 is voltage from power supply (VIN +5V) and pinout 1 is probably VOUT. I`ve looked in many catalogs but it is probably a unique label of the manufacturer. I've been looking for this information for several days. I wonder what is means small letter "b" on the marking? Its means country of production or manufacturer designation? Thank for your help!

[wraper]

Looks like buck converter.

[fzabkar]

I suspect that pin #5 is the feedback pin. If so, then there should be two resistors connecting to this pin -- one to ground, the second to Vout. Measure the voltage at this pin. That should make it a little easier to find the IC. A typical feedback voltage is 0.6V.