LM26484SQX Pulling Too much current with no load applied

user4322801

Other Parts Discussed in Thread: LM26484

Hello,

We wired the LM26484 as described in the datasheet "Typical Application" diagram, and it is not working correctly. We are noticing that it is pulling 1.7A and getting very hot. What could be the issue?

over 8 years ago

0 Sheng Jin over 8 years ago

TI__Expert 3340 points

Hi,

was the device enabled? what is the output voltage when 1.7A current drawing? is there any short on your circuit?

0 user4322801 over 8 years ago in reply to Sheng Jin

Prodigy 90 points

Sheng,

The device was enabled and the voltage was 3.8V at the Buck outputs.There are no shorts--thess outputs go directly to a header to power a peripheral device (which was not connected).

I've removed the device from our circuit, and the short circuit condition has been removed.

0 Sheng Jin over 8 years ago in reply to user4322801

TI__Expert 3340 points

Hi,

I got the schematic from our CAT group for this customer/issue, seems there is an error at LDO output, the FB pin doesn't connect to the output.

0 Ahmad_Rashed over 8 years ago in reply to Sheng Jin

TI__Genius 13567 points

After connecting the FB pin on the LDO correctly he finds the output is around 2.3V but should be 1.1V. One of the buck outputs worked briefly and consumed only 40mA. After testing again and increasing the capacitances of the feedback capacitors the original high current issue returned but only 800mA.

Power management

Power management forum

LM26484SQX Pulling Too much current with no load applied