TPS5450: Unable to disable converter

Jejomar Ildefonso

Part Number: TPS5450
Other Parts Discussed in Thread: TPS5420,

Hi Team,

Need your inputs on our customer's query. They're working with the TPS5450 in a 12V input, 5V output condition. Problem is that the converter does not disable upon pulling ENA pin to ground. 2V output voltage is continuously being measured using the scope probe. There is no inductive or capacitive load in the circuit. The 5V generated by the TPS5420 is the only power source in the circuit so there is no back-power issue or leakage that may contribute to the issue. Can you help us on other possible root cause?

Attached is the schematic for reference. Thanks in advance!

Kind Regards,

Jejomar

x1.pdf

over 3 years ago

0 Daniel Li14 over 3 years ago

TI__Mastermind 27040 points

can you measure the PH , VIn and EN waveform when you pulling ENA to GND? how customer connect to ena , from a MCU IO port, any pull up resistor?

Thanks

0 Daniel Li14 over 3 years ago in reply to Daniel Li14

TI__Mastermind 27040 points

I didn't see the feedback, I will close this question. you can raise this question again if the issue still exist.

Thanks

0 Lee Chen over 3 years ago in reply to Daniel Li14

Prodigy 150 points

Sorry for the late reply.

I do not have the wave forms at hand, but the ENA is connected to a MCU IO pin with a pull up resistor. After some more testing and changes in the circuit by using an external pull up resisotr instead of the MCU built-in one, it works ok now.

Thanks for your attention.

0 Daniel Li14 over 3 years ago in reply to Lee Chen

TI__Mastermind 27040 points

HI Lee

Good to see the issue is solved.

Thanks

Power management

Power management forum

TPS5450: Unable to disable converter