TPS62745: Inductor selection for high effieciency.

Abhi Choksi

Intellectual 500 points

Part Number: TPS62745
Other Parts Discussed in Thread: TPS629210, TPS629210-Q1,

In my application below are input / Output requirement.

Application = Battery operated LORA asset tracking pulsed load kind of application.

Vin = +7.2V(2S LiSoCl2 batteries), Vout = +3.3V, Iout = 210mA.

I want highest efficiency in my application for power conversion but, i am confused in selection of inductor.

As per below Table 3 of datasheet.

Inductor core of "DFE252010" is Iron powder and it has high core losses than other types. But as per application curves it shows efficiency around 90% for Vout=3.3V.

Is that efficiency curves are derived considering inductor listed in table 3?
If DFE252010 is not suitable for high efficiency then please suggest type of inductor which i need to select.

over 2 years ago

0 Nancy Zhang over 2 years ago

TI__Mastermind 45820 points

Hi Abhi,

1. Yes,

2. You can try to use XGL3530-472ME. This inductor is composite core material and lower DCR value from coilcraft.

3. I would recommend our new converter TPS629210-Q1 or TPS629210 in the link as below. We will release them by end of this year. The parts and EVM are available in the website now. TPS629210 has smaller size and optimized performance. The efficiency is higher than 90% with 12Vin, 3.3Vout, 1MHz switching frequency and 4.7uH inductor as below. Please take a look.

https://www.ti.com/product/TPS629210-Q1?keyMatch=TPS629210-Q1&tisearch=search-everything&usecase=GPN

Thanks,

Nancy

0 Abhi Choksi over 2 years ago in reply to Nancy Zhang

Intellectual 500 points

I have space constraint in my board and inductor mentioned in table 3 is suitable for my application as its small size(SMD 1008).

May i get same efficiency(>85%) as shown in datasheet if i use inductor mentioned in table 3?

Will efficiency improve if i use inductor which is mentioned in point 2?

+1 Nancy Zhang over 2 years ago in reply to Abhi Choksi

TI__Mastermind 45820 points

Hi Abhi,

TPS62745 datasheet Fig.6 shows efficiency is higher than 85% at Vin=7.2V, Vout=3.3V, Iout=210mA by using the inductor mentioned in table 3. It should improve the efficiency with lower DCR in point 2, but the size is bigger.

Thanks,

Nancy

0 Abhi Choksi over 2 years ago in reply to Nancy Zhang

Intellectual 500 points

Thanks Nancy.

I will go with Part listed in Table 3.

Power management

Power management forum

TPS62745: Inductor selection for high effieciency.