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3.3kW On Board Charger Requirement

Other Parts Discussed in Thread: TIDM-1007, TIDA-01604, TIDM-PSFB-DCDC

Hello,

We have an On Board Charger requirement. Specification is as follows:

  1. Application: Automotive grade ON Board Charger
  2. Power: 3.3kW
  3. Vin_ac = 90-270VAC
  4. Input Frequency = 47-63 Hz
  5. Vout_dc = 40-60VDC
  6. Nominal Vout_dc = 50.4VDC
  7. Max output current = 63A
  8. System Efficiency = >95% @ 180-270VAC, full load and >96% @ 230VAC, full load

Please suggest the reference design for above specifications.

Is it possible to get 3.3kW output power from wide input i.e. 180-270VAC in On board chargers?

Looking forward for your expert support.

Thanks and Regards,

Vikas Dwivedi

  • Hi Vikas,

    You can check out this design here: 

    https://www.ti.com/seclit/ml/slup348/slup348.pdf

    www.ti.com/.../PMP8740

    I am assigning this to the author if you have any more questions.

    Best regards,

    Nick

  • Hello,

    Thank you for sharing the design.

    Somehow design is not able to meet our efficiency requirement. Please suggest some other ON BOARD CHARGER design for our requirement.

    Thanks and Regards,

    Vikas Dwivedi

  • Hello Vikas,

    If you need >= 95% system efficiency, in VAC range 180-270V, then I suggest to go with CCM totem pole bridgeless PFC (best with GaN), see TIDM-1007 (https://www.ti.com/tool/TIDM-1007?keyMatch=PFC%20KW), which is exactly 3.3KW rated power at high line. In order to get 95% system efficiency, you should have 98% on PFC (and this TIDM is suitable) and 97% on the DC/DC stage. For this stage, considering the fact it is a battery charger, with variable Vout, I suggest to go with phase shift full bridge, see TIDA-020031 (https://www.ti.com/tool/TIDA-020031?keyMatch=&tisearch=search-everything&usecase=refdesign). This is also 3.6KW rated, but delivers 12V, so you may want to redesign it for 50.4V nominal. Please let me know if you need further information.

    Best regards,

    Roberto

  • Dear Roberto,

    Thanks you for detailed response.

    TIDM-1007 is an industrial grade, how we can convert it to automotive grade? 

    Regarding TIDA-020031, I have following queries:

    1. This is an analog design, I will prefer to go with Digital design for better efficiency. Please suggest accordingly.
    2. How we can redesign for 50.4VDC? Is there any design note, please share if you have. 
    3. Can you share the Webench design for the same?

    Looking forward for your expert support.

    Thanks and Regards,

    Vikas Dwivedi

  • Dear Vikas,

    In this case you may want to consider the TIDA reference design TIDA-01604 (https://www.ti.com/tool/TIDA-01604), which is a 6.6KW totem pole PFC specific designed for onboard chargers (therefore uses automotive grade components). I believe that by reducing the number of capacitors on the output, and reducing / changing the active components, you should be able to redesign it for 3.3KW. The related design guide (file:///C:/Users/a0406068/Downloads/TIDUE54B%20(1).PDF) will guide you through the redesign process. Regarding the TIDA-020031, which employs an analog controller, I am not aware we have the equivalent power level with digital controller. We do have a phase shift full bridge project, driven by microcontroller from C2000 series, but with different power level. Probably the best idea is to replace the analog controller from TIDA-020031 and use the one controlling the TIDM-PSFB-DCDC (https://www.ti.com/tool/TIDM-PSFB-DCDC). I suggest also to follow the guidelines available in the TIDA-020031 for the redesign of the power stage only (see link: https://www.ti.com/lit/pdf/tiduey2).

    Please let me know if this method is interesting for you or you need further resources.

    Best regards,

    Roberto