TPS63000: TPS63000DRCR going in short circuit when supplied with 2V

No load is connected, 

Should't the IC go in shutdown in case of undervoltage instead of absorbing 800mA?

Hi  Hassan,

what do you mean about 1A current? just in a short time or continus?

output capacitor should be changed during start-up, that is why there will be a inrush current.

current limit for a lab source is be very different between different equipment, but mostly, it is a RMS limit and output will be builded up without load.

Regards

Tao

Hi Zhang, 

Inrush current is understandable.

But at a voltage of 1.9V or below , it continously abosrbs 800mA-1A. The IC gets very hot. This absobtion is beyond my understanding as I expect the IC to shutdown.

It happens on multiple PCB boards I have.

Hi  Hassan,

could you help to check points as below?

1.this current will disappeare with a larger input voltage? right?

2.swap a new IC to check if this current will disappeare.

Regards

Tao

Hi Zhang, Thank you for the help,

1. Yes, the current absorption is not high if I start with high voltage. Also if I increase the voltage while it is absorbing 800mA, absorbtion goes to normal,

2. At the moment its not possible for me to swap the IC. However later, I will be able to test a different board, For now the two boards I have, present same problem, I am attaching some osciloscope plots below.

Input volage, Set to about 1.8V, Current set to 1300mA on the supply, absobtion around 800mA

Output voltage waveform

Below are some plots of L1-L2

Hi Zhang,

This has greatly improved the performance, I will perform some more tests and mark it as resolved

Thank you

Hi   Hassan,

good news, wait for your update.

Regards

Tao