TLV61070A: The performance is not good under a heavy load

Hi Junghyun,

Are the output caps are ceramic cap or electrolytic capacitor? Please use at least one ceramic cap here, like 22uF, and place the ceramic cap as close as VOUT pin. (You can also share us with your layout so that we can help to check).

And more, is the 200uF necessary for your application? If not, for TLV61070A there's no need to add such a big cap. Using two 22uF/0603 size/10V ceramic cap is enough. 

Regards,

Nathan

We use 100uF ceramic cap and have changed it to 20uF but the problem was not resolved.

I include the layout.

Hi Junghyun,

It seems like to due to the poor layout. As I said, please place the output cap as close as VOUT pin, so the area of SW-COUT-VOUT-GND loop (so called critical, red one below) is as much as small.

You can take this layout as reference.

You can also take this app note for more detailed info about layout.

https://www.ti.com/lit/an/slvaes4/slvaes4.pdf?ts=1697076086366&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTPS61022

Regards,

Nathan

Thanks for your reply

I think the output cap is not too far from VOUT pin in my layout.

Is this small difference such a critical?

Hi Junghyun,

Yes the loop is the most important loop for our IC, you can refer to the app notes I mentioned above.

And the loop in your board is double the size of the recommend one, and more I suggest that you can use a small cap, like 10uF or 22uF paralleled with the big 100 cap, and place the small cap as close as VOUT pin.

Regards,

Nathan