LM5141: Part Number Recommendation

Ryan Winters

Part Number: LM5141
Other Parts Discussed in Thread: LMR51603, LM5190, BQ25186, BQ24172

Tool/software:

I am designing a battery charger board to have a selectable output voltage of 3.95V, 4.0V, 4.05V, and 4.10V. I would like the device to cap the output current to 250mA.
So far the LM5141 looks promising but the current limit seems to be +-9% or so. And the voltage output peak-to-peak ripple is about 40mV which is higher than I would like. I can use the adjustable Vout to choose different resistors to hit each of my output voltage levels.

Can anyone recommend a part to use that would have a tighter current limit accuracy, and tighter/cleaner voltage output than the LM5141? Efficiency doesn't mattery much to me. Vin can be whatever is easiest. I was thinking 5V. And if there is an adjustable output LDO instead of buck regulator I am totally good with that too.

5 months ago

0 Timothy Hegarty 5 months ago

TI__Guru 73502 points

Hi Ryan,

What is the input voltage range here?

Controllers are generally for 10A+, way too complicated for 250mA with external FETs, current sensing, etc.

Take a look at our converter portfolio, e.g. LMR51603 65V, 300mA. You would typically need an external constant current (CC) circuit to regulate the current as needed (and not rely on current limit for that).

Regards,

Tim

0 Ryan Winters 5 months ago in reply to Timothy Hegarty

Prodigy 20 points

I am flexible on input voltage range. I was going to power it from a USB which has a range of 4.5V to 5.5V. But I can do 6V or 12V if that makes things easier.
I will look into external constant current circuits. Are there any ICs that you can recommend to handle the constant current?

0 Timothy Hegarty 5 months ago in reply to Ryan Winters

TI__Guru 73502 points

The LM5190 has CC/CV, but it's a controller with external FETs. I'm not sure what else might be available off of 5V or 12V input. Have you checked our BMS product portfolio?

0 Ryan Winters 5 months ago in reply to Timothy Hegarty

Prodigy 20 points

I am looking now. The BQ25186 looks promising, but I won't have host mcu on the board to control it over I2C.

0 Ryan Winters 5 months ago in reply to Ryan Winters

Prodigy 20 points

I think the bq24172 will work!

0 Ryan Winters 5 months ago in reply to Ryan Winters

Prodigy 20 points

Do you know if there is any reference design material that has component part numbers, or (and this would be amazing) a reference design schematic in Altium?

+1 Timothy Hegarty 5 months ago in reply to Ryan Winters

TI__Guru 73502 points

Ryan,

Recommendation is to submit a separate E2E for information on the BQ part, as it will then be automatically directed to the correct team.

Thank you.

Regards,

Tim

0 Ryan Winters 5 months ago in reply to Timothy Hegarty

Prodigy 20 points

Will do, thank you for the pointer to the battery charger ICs!

0 Timothy Hegarty 5 months ago in reply to Ryan Winters

TI__Guru 73502 points

Great, thank you Ryan.

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LM5141: Part Number Recommendation