Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

Power Management ICs Forum Discussions

HW01
Level 1
10 sign-ins 5 replies posted First like given
Level 1

Hi Team!

In one of the applications, I am using TLE4476D operating both channels sourcing 100mA. While operating the IC at room temperature IC heats up to 70 degrees Celcius. When I test the IC at 60 degrees Celsius, IC starts to shut down and power on repeatedly, to be specific it shutdown every 2 Sec for the duration of the 500mS to 1S. 

 

The same thing is observed in the TLE4267GM IC testing with the same environmental conditions. The output current is 100mA while testing.

 

Kindly tell me the reason for this happening. It will be great if you can provide me with a solution for the same.

I am applying 28.5V at the input of the IC.

 

0 Likes
1 Solution
Vishnu_Nambrath
Moderator
Moderator 50 solutions authored 100 replies posted 5 likes given
Moderator

Hello, 

Max current values are derived  when the device on PCB with 80 × 80 × 1.5 mm3
, 35 μm Cu, 5 μm Sn, and with a  heat sink area of 300 mm2. Can you please double-check you have similar conditions in your PCB? (just adding here the open points discussed in the private chat)

Vishnu_Nambrath_1-1661148416811.png

Regards 
Vishnu N

 

 

View solution in original post

0 Likes
6 Replies
HW01
Level 1
10 sign-ins 5 replies posted First like given
Level 1

Hi Team!

 

I am waiting for your help.

Thank you.

0 Likes
Vishnu_Nambrath
Moderator
Moderator 50 solutions authored 100 replies posted 5 likes given
Moderator

Hello, 

Sorry for the delay in the answer. 
I understand that in your second test case, the ambient temperature is 60C. Can you please let me know the measured IC temperature while shut down?

Regards 
Vishnu

0 Likes
HW01
Level 1
10 sign-ins 5 replies posted First like given
Level 1

Hi Vishnu!

The measured IC temperature is around 110 deg C while shut down. I understand that it is happening because of the triggering of the thermal shutdown mechanism. 

Kindly help me to resolve the problem.

 

Note: In the case of the TLE4476D Each channel is tested individually.

0 Likes
Vishnu_Nambrath
Moderator
Moderator 50 solutions authored 100 replies posted 5 likes given
Moderator

Hello, 

Where is 110C measured? on the GND pad? or top of the IC?

Did you test only one LDO or tested multiple LDOs?

Can you please share the Layout file? At least a screenshot of each layer. 

Regards 
Vishnu  

0 Likes
HW01
Level 1
10 sign-ins 5 replies posted First like given
Level 1

Hi!

Thank you for the reply.

1) The temperature is measured on the top of the IC.

2) We have tested multiple LDOs in the same test environment. We got the same result in every LDO.

3) I am attaching the screenshot of the layout of the Circuit. The board has only two layers with 35um copper layers.

0 Likes
Vishnu_Nambrath
Moderator
Moderator 50 solutions authored 100 replies posted 5 likes given
Moderator

Hello, 

Max current values are derived  when the device on PCB with 80 × 80 × 1.5 mm3
, 35 μm Cu, 5 μm Sn, and with a  heat sink area of 300 mm2. Can you please double-check you have similar conditions in your PCB? (just adding here the open points discussed in the private chat)

Vishnu_Nambrath_1-1661148416811.png

Regards 
Vishnu N

 

 

0 Likes