TPS62873: The efficiency of TPS62873 is relatively low and it requires suggestions

hi Boer,

Thanks for using e2e.

Is the same chip TPS62873 used in the previous design, with the same Vin, Vout and Iload conditions? 

The efficiency is mostly affected by the switching frequency and inductor DCR. Can you please cross check these two parameters from the previous design?

BR,

Jingyi

Previously, the MAX77812 was used. Currently, it shows that the overall power consumption is about 2W higher than that of the MAX77812. Please help review the schematic diagram

Hi,

I see. 
To have higher efficiency, the customer can change the Fsw to 1.5MHz by changing the FSEL pin to 'short to GND'.

To review the external compensation circuit, can you pls provide the load transient condition (Imax, Imin and slew rate)?

BR,

Jingyi

The current of 0.65V is typical for 3.3A, with a maximum of 4.2A; the current of 0.94V is typically 3.6A, with a maximum of 4A.

hi,

Could you also provide the slew rate? For now I would assume the rising time is 1us.

BR,

Jingyi

Hi,

Can you please confirm if the schematic contains all the output capacitors, at the output of DCDC BUCK and on the load side?

If not, please provide the entire output capacitors.

BR,

Jingyi

Yes, it includes all the output capacitors

Hi,

I see. Then please change the Rcomp to 50 ohm and Ccomp to 3nF. Here is the calculator sheet I used: 

TPSM8287AComponentCalculator - .xlsx

To increase the efficiency, please consider changing the Fsw to 1.5MHz.

BR,

Jingyi