LM5045: Minimum Switching Frequency

Hi Kuan,

The LM5045 is characterised down to about 200kHz oscillator frequency or a switching frequency of 100kHz. 

if we look at figure 6 on page 10 of the datasheet, the frequency curve versus Rt is beginning to flatten out when Rt = 50k, to run at 60kHz the Rt is going to be much bigger and because the curve will now be quite flat there will be more variation in the switching frequency.

The UCC28951 is also a phase shifted full bridge controller and can be run at lower switching frequencies for high power and high voltage applications, perhaps this is a better part to use for your application?

Regards

Peter

Dear Peter,

Thanks for the input.

The customer is looking for full bridge controller can operate at 60kHz.

They don't want phase shift full bridge.

Do you have any suggestion?

Br

Kevin