PMP7282: 30V - 1000VDC to 12VDC high efficiency (>95%) DC step down converter >= 600W

Hello,

I will follow up with the product expert and provide feedback on what newer products could act as a replacement for LM5116.

Best Regards,
Katelyn Wiggenhorn

Hello,

One additional question, what is your input voltage range? Are you looking for a device which supports 35-V to 60-V input, or are you looking for a 1000-V input?

Best Regards,
Katelyn

Hi Katelyn,

Thanks for following up!

If there are certain requirements to gain >97%+ efficiency, we can tailor the input to that range, but I'd like to be as adaptable as possible.

Right now for our project, the input range can vary between 30VDC -1000VDC. In actuality it will be anywhere in that range +/- 10VDC. It comes down to wiring losses which become meaningful based on the distance from the power source to where its being used.

ex: one system may have an input at 70VDC +/- 10VDC ( 60VDC - 80VDC)

another system may have 380VDC +/- 10VDC (370VDC - 390VDC)

Does that make sense?

The other thing about the PMP7282 design is it puts out a lot of heat! It gets over 100 C at 50A load based on the test data. I was hoping new devices could help get into a more manageable range (~50 C) or if we could parallelize the boards (PMP7282 reaches peak efficiency @ 30 A) to achieve the same while maintaining modularity.

Kind regards,

sug

Hello,

One option may be the LM5140-Q1 65V synchronous dual controller that can be configured as a two-phase implementation. The LM5146-Q1 may also be a possibility. Note that the 12V output can feed the VCC of the LM5146-Q1 to reduce IC power consumption. See this blog to configure as a two-phase implementation:

e2e.ti.com/.../how-to-design-a-simple-two-phase-current-sharing-synchronous-buck-regulator-using-a-voltage-mode-controller

What is the output current requirement? Maybe an efficient single-phase implementation is feasible. 

Regards,

Tim

Hi Tim,

Thanks for the link, it was helpful.

I overlooked the potential phase shift from parallelized DC-DC converters. I figured a system that took multiple DC 12V outputs and then fed into a regulator would suffice but this is a potential for efficiency gains or losses depending on how its handled.

Each system/unit will require 550W - 600W. [edit: we may be able to optimize each system to ~450W but I'd like to allow for a margin]
Some devices will use far less, ~150W. They can be handled with conventional products or bundled to reach similar power usage.

Kind regards,

sug