UC3845: Boot converter with paralleling

mudit mittal

Part Number: UC3845
Other Parts Discussed in Thread: UC3907, , UCC29002

Hi,

we are designing a boost converter with 3kw output ,for modularity I break down the power requirement of 1500W each . in order to provide 3000w i am just paralleling the converter. for parallel operation i am planning to use LM5080 or UC3907.

can you recommend any other ic or how to effectively used these ic for parallels operation.

my input is 40V and boost out put is 48V , for boost converter i am using UC3845

Regards

Mudit

over 1 year ago

0 JCHK over 1 year ago

TI__Mastermind 44620 points

Hi Mudit,

If you are looking for a sharing controller we have our UCC29002.

At this power level, normally we recommend a phase-shifted full bridge. Here is a reference design that seems to be close to what you are looking for: PMP6712. This is using our UCC28950 as the primary controller.

I hope this answers your question.

0 mudit mittal over 1 year ago in reply to JCHK

Prodigy 30 points

The system is non isolated ,so as par my understanding phase shifted full bridge will not work .

any recommendation / critical point to be taken care while designing parallel systems

Also UCC29002 use high side sensing for current share. as par the datasheet CS+ and CS- the voltage will not be higher than 15V

since my output voltage will be 48V ,shall i have to use low side current sensing .pls provide

0 JCHK over 1 year ago in reply to mudit mittal

TI__Mastermind 44620 points

HI Mudit,

Figure 5 on page 11 of the UCC29002 datasheet shows an example of using the load-share controller in higher voltage systems.

Do you think this can work for you?

0 mudit mittal over 1 year ago in reply to JCHK

Prodigy 30 points

Dear All

can you provide some suggestion how to implement programmable current limit and shutdown mode in uc3845

Regards

Mudit

0 JCHK over 1 year ago in reply to mudit mittal

TI__Mastermind 44620 points

Hi Mudit,

I am not sure how you want to control the current limit, but here is an example to create two thresholds. To disable the controller the VCC pin needs to be pulled below the UVLO.

I hope this answers your question.

Power management

Power management forum

UC3845: Boot converter with paralleling