Part Number: TPS62130A
I need some help, the attached is a screen snip of a regulator design that we use everywhere across many products, only the voltages are different. We use this same circuit to create voltages from 0.95V to 5.0V and never had any issues. This circuit I’ve attached is used to supply power to a Macom MAXP-23004 SDI cross point IC. We have boards that sometimes this particular supply does not come up all the way and stops is regulation at ~0.6V. I have looked at all of the pins and they seem to look normal with the exception of the FB pin 5 which is a 0.4V on units that do not power up correctly. On the schematic you can see I have put a low value resistor in series with the regulator input pins to measure input current, and through calculations and a rough guess as to the efficiency you can get an idea as to the output current of the regulator. During a correct power up the output current is ~1.8amps (the P_RAIL voltage is 12V) and on an incorrect power up the output current is ~1.0amps, so it appears that the output of the regulator is not being clamped or held to .6V by an external device other wise the regulator would be drawing more current and go into current limit. What do you think is going on here? Can you or anyone on the team help me with this? Do you think this part may be failing? Any feed back would be appreciated.
Mike Richardson
Cobalt Digital
