TPS23758: TPS23758:PD input is always 0>52>0>52>0....,output is always 0>9>0>9>0...

ma yuan

Part Number: TPS23758
Other Parts Discussed in Thread: TIDA-010083,

I want to use the tps23758 to transfer a PSE(48V) to 5V output,the board tida-010083 is used for reference circuit.The circuit is as shown below.

D20、R66、F10 is not conneted now.

The supply 48V voltage waveform is as shown below.

The output 12V voltage waveform is as shown below.

At first, I suspect it was a short circuit,but i can‘t find any place is shorted.I also use a Stable 48V power supply as input,there is no damage to any parts and the output voltage is always 0,VCC is always 13V(when PSE input,it,s 13>8>0>13>8>0....).

I try to add a load in the output,it,s also no use.Do you have any ideas?

over 3 years ago

0 ma yuan over 3 years ago

Prodigy 10 points

the wave transfer output is below.

0 Brett Colteaux over 3 years ago in reply to ma yuan

TI__Expert 3700 points

Hi,

Thank you for your question.

I took a look at the schematic and a few things caught my eye. I recommend changing C57 to 22nF and also changing D22 to zener. I also recommend adding a 0.22uF cap from VDD pin to RTN.

Could you also take a waveform of VSS_RTN and also DRAIN_RTN? I think this will help us to understand where the issue is happening.

Best Regards,

Brett Colteaux

Power management

Power management forum

TPS23758: TPS23758:PD input is always 0>52>0>52>0....,output is always 0>9>0>9>0...