WEBENCH® Tools/LMZ14201H: Can we use LMZ14201H as a negative in negative out buck converter?

Benyuan Liu

Part Number: LMZ14201H
Other Parts Discussed in Thread: TPS7A44, TPS7A33, , LMZ14202H, LMZ14203H, TPS7A47, TPS40210, PMP9624

Tool/software: WEBENCH® Design Tools

We want to convert a +24V, GND, -24V power input to +16V, GND, -16V and fed them into LDO (TPS7A33, TPS7a44) for maximum efficiency. Can I use LMZ14201H as a negative buck? that it converts -24V to -16V?

over 5 years ago

0 Denislav Petkov over 5 years ago

TI__Mastermind 18940 points

Hello byliu,

The LMZ14201H (1A in Buck config) can be used in inverting configuration. The LMZ14202H (2A in Buck config) and LMZ14203H (3A in Buck config) are pin-to-pin compatible and can also be used if the current requirements in inverting demand higher current rating.

You cannot convert the -24V to -16V with this part.

What you can do is step down from +24V to +16V first with one LMZ1420xH module.

Then convert the +16V to -16V with another LMZ1420xH module.

You can use the WEBENCH tool on this page to experiment with the specifications and get a design:

and use the entry panel to enter your specifications for Buck and Inverting:

Cheers,

Denislav

0 Benyuan Liu over 5 years ago in reply to Denislav Petkov

Intellectual 595 points

Does TI have any solution in generating -16V from -25V? We need this part for maximum thermal/heat designs using LDOs such as TPS7a33 and TPS7a47

0 Denislav Petkov over 5 years ago in reply to Benyuan Liu

TI__Mastermind 18940 points

Hello byliu,

You would need a boost converter for this. Here is one example with the TPS40210 boost controller.
http://www.ti.com/tool/PMP9624

Cheers,
Denislav

0 Benyuan Liu over 5 years ago in reply to Denislav Petkov

Intellectual 595 points

PMP9624 uses discrete components, which is hard for a beginner like me. It would be of great value if TI had any plans in releasing a SIMPLE or SWIFT power switches which accept negative input and produce bucked/boost negative output.

Thanks!

0 Jimmy Hua over 4 years ago in reply to Benyuan Liu

TI__Mastermind 47060 points

Hi byliu,

Thank you for your feedback. We will take that into consideration for future roadmap device discussions. As of right now the power module's team is primarily focused on creating buck modules.

Regards,
Jimmy

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WEBENCH® Tools/LMZ14201H: Can we use LMZ14201H as a negative in negative out buck converter?