TPS61088 temperature rise

We run a test with input voltage higher than output and the silicon got very hot .  Can you explain this power dissipation. Thanks a lot!

Test condition:

Vin = (12V);

Set Tps61088 Vout is 9V,but actual Vout is 11.4V;

Iout = 0.5A;

the max voltage of EN is 7V, what's this voltage at your test?

what's the voltage drop between SW pin and Vout pin?

Yuan Wu1

We run a test with input voltage higher than output and the silicon got very hot .  Can you explain this power dissipation. Thanks a lot!

Test condition:

Vin = (12V);

Set Tps61088 Vout is 9V,but actual Vout is 11.4V;

Iout = 0.5A;

Hi buddy,

The chip is a boost converter..why you use it as a buck converter? so the voltage should be 11.4V. thank you.

Hi Yuan,

You know the power is from two parts. The Vin to Vout. The power is 0.3w. The other is the IQ. It's smaller. The temperature should not be too high.I think you should take care the solder. The problem may happen there. Thank you.

For the deyisupport, Chinese is ok too. You needn't  to use English to ask the question. thank you.

Dear Land and Max Han ，

     非常感谢您的回复！

     主要是由于客户要求输入电压范围比较宽，6～13.5V，稳压在9V，如果输入超过9V，直接输出输入的电压，因为规格书中第8.4.1节说明了IC内部的high-side NMOS存在 body diode，当输入超过设定的输出电压时，认为输入电压可以通过此二极管直接过来 ，所以以为是可以做的，但是实际测试发现一旦电压超过12.6V，比如说13.5V，IC的输出始终维持在12.6V，即使只输出0.5A的电流，IC在1分钟左右温度也会升高到60度。因为IC的推荐输入电压是 2.7V～12V，但是最大输入电压可以到14.5V。想确认下IC是否可以支持到13.5V的输入，发热是否是由于IC本身的设计只能输入2.7～12V，超过12V，比如说13.5V时IC比较容易损坏。

感谢！

你好，损坏倒是不会，发热应该是主要来自我之前谈到的几点，不确定芯片内部是不是有TVS类似的东西来钳位，一般情况是没有的，谢谢。

我认为是可以支持到13.5V输入的，至少不会硬损坏，谢谢。