UCC3895 min frequency

Arman Bzishkyan

Other Parts Discussed in Thread: UCC3895, UCC28950, UC3875

HI all,

I am developing FB-PS-ZVS DC/DC boost converter with high power IGBT modules for more than 30kw. The operating frequency must be 10 - 20 khz

Actually I am not familiar with DSP yet and i am going to use UCC3895

Does UCC3895 really works on such low frequnecies? or may be there is better solution FB-PS controller for such frequencies?

Thank you

over 7 years ago

0 Daniel Ruiz over 7 years ago

TI__Intellectual 2910 points

Hi Arman,

I have contacted the applications team for this device to help address your request.

Regards,

- Daniel

0 Arman Bzishkyan over 7 years ago in reply to Daniel Ruiz

Prodigy 90 points

Thank you Daniel

0 Oliver Pan91 over 7 years ago in reply to Arman Bzishkyan

TI__Intellectual 2230 points

Hi Arman,

The UCC28950 is the enhanced version of UCC3895, it can operate at switching frequency as low as 50kHz, is this frequency can satisfy your requirements?

Thanks,
Oliver

0 Arman Bzishkyan over 7 years ago in reply to Oliver Pan91

Prodigy 90 points

HI Oliver

Requirements for frequency of FB-PS-ZVS- DC/DC (600V / 30KV) boost converter are 10khz (20khz max).

0 Oliver Pan91 over 7 years ago in reply to Arman Bzishkyan

TI__Intellectual 2230 points

Hi Arman,

If so you may consider the UC3875: www.ti.com/.../uc3875.pdf

Thanks
Oliver

0 Arman Bzishkyan over 7 years ago in reply to Oliver Pan91

Prodigy 90 points

Oliver, i read the datasheet UC3875, it operates up to 1 mhz as well as UCC3895, why do you think that UC3875 can operate at 10khz ? may be i missed something in datasheet

0 Oliver Pan91 over 7 years ago in reply to Arman Bzishkyan

TI__Intellectual 2230 points

Hi Arman,

If you see the curve of Oscillator frequency vs RT&CT in below figure, you will find the oscillator frequency(twice of switching frequency) goes to 20kHz when CT=4700pF and RT ~= 85kohm.

Thanks

Oliver

0 Arman Bzishkyan over 7 years ago in reply to Oliver Pan91

Prodigy 90 points

Thanks Oliver

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UCC3895 min frequency