WEBENCH® Tools/LMR23615: PFM mode efficiency

Diwakar Karunagaran

Part Number: LMR23615
Other Parts Discussed in Thread: LMR33620

Tool/software: WEBENCH® Design Tools

Hi ,

What is the minimum current that LMR23615 IC support during PFM mode. Our application operates in sleep mode for most of the time. So kindly confirm the minimum load current supported in PFM mode and efficiency at PFM.

Thanks in advance.

over 5 years ago

0 Marshall_Beck over 5 years ago

TI__Mastermind 34770 points

LMR23615 will continue to regulate at 0A load current.

Efficiency curves in datasheet reflect efficiency at light load with pfm mode enabled down to 100uA.

See electrical characteristics table for pfm iQ.

0 Diwakar Karunagaran over 5 years ago in reply to Marshall_Beck

Prodigy 180 points

Hi Marshall,

As per the efficiency curve in the datasheet, The efficiency goes to a very low value in of up to 20% for a 24 V input. In our case

Vin = 24 V , Vout = 5V . We are having a battery powered product which is in sleep mode for most of the time. We need a better efficiency to improve our battery backup time. So should we choose some other switcher? Is there any series with a better efficiency at very low loads,Please suggest if there are any.

Thanks in advance.

0 Marshall_Beck over 5 years ago in reply to Diwakar Karunagaran

TI__Mastermind 34770 points

Understood. LMR33620 may be good choice?

http://www.ti.com/lit/ds/symlink/lmr33620.pdf

0 Diwakar Karunagaran over 5 years ago in reply to Marshall_Beck

Prodigy 180 points

Hi Marshal,

Thank you for the suggestion, But there is no efficiency curve in the datasheet of LMR33620 for low current values lesser than 1mA. Can you confirm the efficiency of this switcher at load currents lower than 1mA.