LMG3411R050: Can the LMG3411R050/LMG3411EVM-018 work at 1.5MHz switching frequency?

Suiyang Hu

Prodigy 195 points

Part Number: LMG3411R050
Other Parts Discussed in Thread: LMG3411EVM-018,

Hi，expert

I want to use Ti GaN in my project, so I bought the LMG3411EVM-018 evaluation board.

My question is what is the maximum switching frequency limit for the LMG3411EVM-018, or for the LMG3411R050 device?

Considering of the limitation of the Buck-Boost circuit inside the device, Can it work at 1.5MHz or 1.2MHz?

Best regard.

Suiyang.

over 3 years ago

0 Suiyang Hu over 3 years ago

Prodigy 195 points

In LMG3411EVM-018 User's Guide,It refer “ Maximum recommended operating inductor current of 8A”.

But in the datasheet of LMG3411r050 ,the Recommended IDS is 12A. Why is there a difference between the two note.

if i use the EVM board in a single phase CrM mode totem-pole pfc circuit,Considering the TCM inductor current waveform, So what is the maximum power rating in that application?

Thank you very much.

0 Suiyang Hu over 3 years ago

Prodigy 195 points

I need some help

0 Noah Rodriguez over 3 years ago in reply to Suiyang Hu

TI__Intellectual 1341 points

Hi Suiyang,

Thank you for your questions. The typical value for switching frequency on this device is 750 MHz, so we cannot recommend operation at the frequencies you have mentioned.

As for your second question, the 8A limit comes from the inductor used on the EVM. However, the device has a higher current rating as you mentioned. Therefore, if you use a different inductor with a higher current rating, you would be able to reach the 12A mentioned in the device datasheet.

Thanks,

Noah

0 Suiyang Hu over 3 years ago in reply to Noah Rodriguez

Prodigy 195 points

Hi Noah

Thank you for your kindly reply.

Does the maximum IDS value refer to the current peak value or the RMS value?

As we known, Between CrM mode and CCM mode condition , Its current is quite different, So what parameter should I use to evaluate the IDS max.

About switching frequency , you mean the max recommend operation is at 750kHz?

Best regard.

Suiyang

+1 Noah Rodriguez over 3 years ago in reply to Suiyang Hu

TI__Intellectual 1341 points

Hi Suiyang,

The maximum IDS value is referring to the current peak value.

The 750 kHz is the typical recommended value. We have previously recommended a max frequency of about 1.2 MHz for this device.

Thanks,

Noah

Power management

Power management forum

LMG3411R050: Can the LMG3411R050/LMG3411EVM-018 work at 1.5MHz switching frequency?