LM5122 - Webench allows only sw- frequency lower 260kHz

Josef Warta

Expert 4390 points

Hello Team,

tried to setup a design with 9..16Vin and 25Vout/5Amp, everything else default.

But I get only switching frequency up to 260kHz. Is there any reason why? I need round about 400kHz.

Thanks

Josef

over 9 years ago

0 Britt Brooks - Online Design Tools over 9 years ago

TI__Mastermind 41310 points

Josef,

Let me check on this. The duty cycle limit states 720K for fsw for your conditions.

0 Howard Chen-WEBENCH Design Center over 9 years ago

TI__Expert 6365 points

Hi Josef,

For power designs in WEBENCH, one of the critical element is checking the operating temperatures of a design whether it can be created. If so, it may limit the max. frequency. The reference point of this is the ambient temperature setting in the GUI to assure it doesn't exceed the any of the components rating. BTW, Theta JA is only specification is used unless otherwise noted.

For your inputs, set the ambient temperature = 0 deg. C and it should create a design with switching frequency over 400 kHz.

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LM5122 - Webench allows only sw- frequency lower 260kHz