TPS54231 VS TPS5430

What are the conditions and what is the circuit? Can you post your schematics?

Hi John, 

                 Please see circuit, the output waveform is normal?

Hi John,

                    This is tps5430 circuit, similar EVM BOARD, current consumption is about 350mA, so there may be in the Eco-made? thanks.

 

It is difficult to answer. I can tell you that in eco-mode the ripple is greater. I would have to know all the details including the COMP pin voltage.

Hi John,
Could you please tell me how to confirm that it is to enter the ECO-MODE?
Which measurement signal? Thanks

You have to look at the SW node waveform. In CCM you will see a rectangular pulse waveform. For TPS54231, the switching frequency is typically 570 kHz. As the load decreases below ILp-p/2, the device will enter DCM. You will see the characteristic DCM waveform where the inductor current goes to zero and the SW node voltage rings prior to the beginning of the next on time. It should still be at 570 kHz. When the load is further decreased, the COMP pin voltage goes to the minimum clamp. At this point the device enters eco-mode. You should see the apparent switching frequency decrease as the load decreases.