TPSM84624EVM-013: TPSM84624 4.5-V to 17-V Input, 0.6-V to 10-V Output, 6-A Power Module

Hello,

If you look at Figure 4-1 in the EVM user guide (https://www.ti.com/lit/ug/snvu581b/snvu581b.pdf), for 12V input at 1V with 400kHz switching frequency, the efficiency is around 82.5% at 6A. The default EVM configuration is at 450kHz so I would expect the efficiency to be lower and may be even reaches 79%. If you want to use 400kHz switching frequency, the only option is to change R12 (on bottom layer) to 124kohm from the current 110kohm and then try again. I would expect an efficiency bump with that lower 400kHz switching frequency if nothing else on the EVM was changed. Let me know if this helps. 

Thanks,

Amod

Thanks Amod. 

I will check and update you if this helps.

One more important data, Sorry I didn't mention, to get 1V, I did what mentioned the first row  in table 2-1, so I changed the jumpers p1, p2 and p3 accordingly. 

Hi Shitaye,

Yep jumper setting for 1V is good. The frequency setting however is at 450kHz on the EVM while the data show in datasheet is 400kHz. So, swapping the R12 to 124kohm will change the 450kHz jumper setting to 400kHz. Lowering the frequency may help increase the efficiency. If you can, please take a picture of the final board configuration with jumpers and send it so I can check how the settings are.

Thank you,

Amod

Thanks for your reply, 

 I moved the jumper P1 to the top, 350Khz (please refer to the picture below), based on the recommendation in datasheet  Table 2-1 . what did I miss?

I was under the impression you needed to check efficiency at 400kHz. Jumper setting is fine at 350kHz for 1V. With this 350kHz setting the efficiency should be slightly higher than the 400kHz data shown in the user guide for 1V. I can check on the EVM here too but can you post your input voltage, input current, output voltage and output current raw data you took here?  

Thanks,

Amod 

Nominal value:

Nominal  Input Voltage 12V (11.96V)

input current ~300mA (0.308A)

Nominal  output voltage 1V (0.951V)

Output current 3A (I used electronics load) (3.097A)

frequency of operation 350Khz.

Measured values are in the bracket.

I used a DVM to measure the |input and output values.

and the current on the input and output  were measured using current probe.

The input current was measured using multimeter.

given this detail above expected even higher efficiency than what appeared in datasheet (see the graph) - Isn't? 

Hello,

Please allow until next week for a response due to holidays.

Thanks,

Calan