LM3492: Use this chip as Buck (Step-down)

Ryan Delfino

Prodigy 150 points

Part Number: LM3492

Hi,

I want to use LED driver LM3492HC two drive to LED strings in my design.

The spec says that it is a boost, but I would like to use it as a step down (buck)

Example: 48V input with 35V output driving 200mA.

I asked Customer Support about this but they suggested to post my query in this forum instead.

Looking forward for some advice.

Thanks.

Regards,

Ryan

over 4 years ago

0 Irwin Nederbragt over 4 years ago

TI__Mastermind 28655 points

Hello Ryan,

This is a boost with an internal MOSFET pulling to ground. There is no easy way to use this as a buck.

Are you driving two LED strings? If so what are the operating conditions for your output?

What are you planning on using this for?

Best Regards,

0 Ryan Delfino over 4 years ago in reply to Irwin Nederbragt

Prodigy 150 points

Hi Irwin,

Thanks for your feedback, I appreciate it.

Yes, I plan to drive two LED strings. Each string contains 28 LEDs with each string voltage equal 36V.

We plan to use this in light therapy application

Regards,

Ryan

0 Irwin Nederbragt over 4 years ago in reply to Ryan Delfino

TI__Mastermind 28655 points

Hello Ryan,

You could look at using two TPS92515AHV LED drivers.

Best Regards,

0 Irwin Nederbragt over 4 years ago in reply to Irwin Nederbragt

TI__Mastermind 28655 points

Hello Ryan,

I haven’t heard back from you, I’m assuming you were able to resolve your issue.
If not, just post a reply below (or create a new thread if the thread has locked due to time-out)

Best Regards,

Power management

Power management forum

LM3492: Use this chip as Buck (Step-down)