• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 150 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

330-450VDC to 12 VDC solutions, FSAE accumulator

Ivan Starcic
Prodigy 10 points
Other Parts Discussed in Thread: UCC25660, UCC25660EVM-064, UCC28951

Hi,

I'm a student in FSAE. We are building our first electric car. My task is designing a PCB which will convert high voltage from the accumulator to low voltage to power all of the low voltage systems(roughly 250W of power and 12VDC). Converter will probably have to be flyback. I have previously successfully designed multiple PCB's  but all low voltage I know roughly what to do I just need a few references to parts, papers and software. I just need a rough start guide and I will figure out the rest on my own. For the first time I'm actually making something dangerous 450VDC is no joke.   

Thanks

Ivan Starčić

University of Rijeka, Riteh Racing Team 

  • 0
    TI__Expert 4170 points

    Hello Ivan,

    Summary of requirements:

    • Vin: 330V - 450VDC
    • Vout: 12VDC
    • Pout: 250W

    Congratulations on your first time designing a high power and high voltage system! Yes, it is dangerous but TI provides numerous resources and examples for you to get started. As a note, anytime you have high voltage you will want to include isolation AKA a transformer. This ensures that the high voltage input (Ex. 450VDC) is isolated from the low voltage output (Ex. 12V). So, if you have a short or power surge on the high voltage input, it will not affect the low voltage output. 

    Luckily, these requirements closely match common offline AC/DC applications. Anytime you want to power something from a typical AC source, we call that an "offline AC/DC". Because the world uses 110VAC to 220VAC, we have an input voltage range of 85VAC - 265VAC as the "universal AC input". This universal AC input is rectified to DC voltage and then boosted to ~390VDC in a Power Factor Correction. Afterwards, to charge things such as your refrigerator, TV, etc., we convert 390VDC to low voltage, such as 12V. These 390VDC to 12VDC topologies are typically either LLC or Phase Shifted Full Bridge (PSFB) depending on the power level. At 250W, I recommend LLC. See our high voltage controller map here: https://www.ti.com/power-management/acdc-isolated-dcdc-switching-regulators/overview.html.  

    One of our newest products closely matches your requirements. The UCC25660 (https://www.ti.com/product/UCC25660) is a new LLC controller with wide input voltage and output voltage ranges. You can buy or view the schematic of the UCC25660EVM-064 (https://www.ti.com/tool/UCC25660EVM-064), which demonstrates the UCC25660 with the following parameters:

    • Vin: 390VDC
    • Vout: 12VDC
    • Pout: 180W

    You can use the UCC25660EVM-064 as a starting point and change values based on Power Stage Designer (https://www.ti.com/tool/POWERSTAGE-DESIGNER). See the example below.

    You can also view our Reference Design Library here: https://www.ti.com/reference-designs/index.html. Type in your requirements and you can browse numerous reference designs. While the boards are not available for sale, the schematics and test reports are available. You can also try using Webench (https://webench.ti.com/power-designer/switching-regulator) to automatically generate schematics. Here is an example of a generated design using the UCC28951 (https://www.ti.com/product/UCC28951) PSFB controller: https://webench.ti.com/appinfo/webench/scripts/SDP.cgi?ID=8DC13AB03F99E791  

    Please ensure you are using proper safety procedures when evaluating the hardware. I recommend an isolation box with a relay to your DC supply. So, if the isolation box opens, the DC supply will automatically shut off. Here are some resources on safety: https://safety.ep.wisc.edu/hazards/high-voltage-safety 

    Regards,

    Jonathan Wong