I'm troubleshooting a circuit that uses the ptn78000h to generate +15 VDC from an input voltage of +28 VDC. I suspect this circuit is drawing too much DC current from
the +28 VDC power supply. I'm using a bench power supply to provide the +28 VDC with the supply's overcurrent protection set to +1.0 amp.
As soon as I turn on the +28 VDC power supply output, the overcurrent protection is tripped. What is the specfication on the ptn78000h's start up inrush current?
Thanks for your help.
PTN78000 series normally soft start can sink current up to 1 amp in duration of 3-5ms from the 28V power source. The in-rush current amplitude is also dependent upon the input and output capacitance plus the ramp-up rate of the 28V power source. From the brief in-rush current description , the module appears to operating normally.
Tom
tguerin@ti.com