1u High Power PSU Design

Kok Khuan P'ng

Other Parts Discussed in Thread: UCD3138, UCC28070A, UCC28180, UCC28950, UCC25600, UCC28251

Hi TI,

I am in the beginning of designing a 1u height PSU that can deliver up 1200W output power. It is almost similar to the PSU datasheet attached.

With this low profile, a high efficiency at least 95% for DC/DC and 95% for PFC is needed so that the heatsink size is small enough. Combining these 2 efficiency, the total efficiency of whole PSU should be more than 90% at rated load.

Do you have any design idea (what topologies, which TI IC) for the PFC and for the DC/DC that is in small form factor and can deliver 95% efficiency?

Regards,

over 9 years ago

0 Kok Khuan P'ng over 9 years ago

Intellectual 450 points

HI TI,

Forgot to attach the datasheet.6371.uMP series iu Multi Output 1200W (Emerson).pdf

0 Yunsheng Qu over 9 years ago in reply to Kok Khuan P'ng

TI__Genius 9790 points

Hi, KK

How many channels of output, and waht is the output voltage and maxmum current of each output?

For you application, TI has UCD3138 to promote to you. UCD3138 is a digital controller, but needs litter firmware work to do. UCD3138 has PMBUS communicaiton interface, can meet your requirement.

For topology, I recommend single Phase or interleaved PFC(is good for power density) for the first stage, and can meet 95% efficiency requirement. For secondary stage, LLC is reocmmended, can meet 96% efficiency requirement.

TI has PFC and LLC demo board with UCD3138.

Regards,

Yunsheng

0 Kok Khuan P'ng over 9 years ago in reply to Yunsheng Qu

Intellectual 450 points

Hi Yunsheng,

There will be 6 slots which can have max. up to 12 outputs. The slots are exchangeable for choosing the right output voltage. The slots can be paralleled to provide higher output power. Each slot is adjustable from its configured min voltage to max voltage. There can be that 1 slot will have 2 output voltages and another slot can have only 1 output voltage, but can deliver higher output power.

I don't think UCD3138 can deliver this solution.

Regards,

0 Yunsheng Qu over 9 years ago in reply to Kok Khuan P'ng

TI__Genius 9790 points

Hi, KK

It is a big system, UCD3138 may cannot all the function of your project, but for PFC, UCD3138 is a good solution.

Is there a PFC for each slot, or only one PFC for 6 slots?

regards,

yunsheng

0 Kok Khuan P'ng over 9 years ago in reply to Yunsheng Qu

Intellectual 450 points

Hi Yunsheng,

Only 1 PFC for 6 slots.

And I don't think UCD3138 is suitable for PFC because it can deliver more combination of functions. It may be over design by using UCD3138 for PFC only.

Regards,

0 Kok Khuan P'ng over 9 years ago in reply to Kok Khuan P'ng

Intellectual 450 points

Hi Yunsheng,

Do you have any suggestion for the PFC IC and PWM IC besides UCD3138?

Regards,

0 Yunsheng Qu over 9 years ago in reply to Kok Khuan P'ng

TI__Genius 9790 points

hi, KK

for PFC IC, besdes UCD3138, there are UCC28180 for single phase CCM, and UCC28070A for two phases interleaved CCM PFC.

PWM IC, what topology you want to use for DC/DC stage?

regards,

yunsheng

0 Kok Khuan P'ng over 9 years ago in reply to Yunsheng Qu

Intellectual 450 points

Hi Yunsheng,

For DC/DC, it must be a topology that can meet efficiency of 95% in small form factor.

Any topology can meet these requirements?

Regards,

0 Yunsheng Qu over 9 years ago in reply to Kok Khuan P'ng

TI__Genius 9790 points

hi, KK

there are three options:

1.Phase shift full bridge, TI has UCC28950 to realize this topology

2.LLC, UCC25600 is for this topology

3. Half bridge, UCC28251 is for this topology

regards,

yunsheng

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1u High Power PSU Design