TPS61230 efficiency data

hong ni

Other Parts Discussed in Thread: TPS62080

I have a question about the efficiency data on page 7of datasheet,figure5.

why the 2.4VIN efficiency is lower than VIN3.3V. I have checked the rdson, it's same for high side and low side FET.so duty cycle is not the reason. can any one share your ideas? thanks.

over 11 years ago

0 Jasper Li over 11 years ago

TI__Mastermind 46905 points

the input current is higher for Vin=2.4V, so the mosfet conductive loss is higher.

jasper li

0 hong ni over 11 years ago in reply to Jasper Li

Prodigy 70 points

but for tps62080 on datasheet figure6,why 5VIN gives lowest efficiency?

0 Jasper Li over 11 years ago in reply to hong ni

TI__Mastermind 46905 points

TPS62080 is a buck converter, the inductor current doesn't change with Vin. and the switching frequency is highest at Vin=5V, so the power loss is highest.

jasper li

0 hong ni over 11 years ago in reply to Jasper Li

Prodigy 70 points

but for heavy load,frequency is not the key thing determine efficiency?

frequency only matters at light load....

but 5VIN has lowest efficiency for whole load range

why?

0 Jasper Li over 11 years ago in reply to hong ni

TI__Mastermind 46905 points

the switching loss could be a large portion of the total loss in heavy load, if the switching frequency is very high. for TPS62080, the frequency at Vin = 5 reach 3MHz, and only 1Mhz at Vin=3.3V, this is the reason of the efficiency curve. you can refer datasheet figure 22 about the frequency.

jasper li

Power management

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TPS61230 efficiency data