Forum Post: Re [2]: LM46002 in WEBENCH Designer Problem with assigning of switching frequency

Hello Sergey,

An LM46002 design with the specs of Vin=40 to 56V, Vout=3.3V, Iout=0.5A, and fsw=1MHz to 1.5MHz fails to be created because of Ton_min and Toff_min.

We follow these equations

FswMax_based_on_TonMin = Vout / (VinMax*TonMin) = 471.4kHz

FswMax_based_on_ToffMin = (VinMax-Vout) / (VinMax*ToffMin) = 470.5kHz

WEBENCH Power Designer suggests TPS54060 for the corrected test conditions

I would recommend TPS54060A because it has better ESD performance.

Best Regards,

Flora