• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 63 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

LM5034: +400V generation for switching circuits

Sivadharshan Kamaraj
Prodigy 60 points
Part Number: LM5034
Other Parts Discussed in Thread: UCC2808A-2

Tool/software:

Hi,

        I have planned to generate +400V from +12V using LM5034.  This 400V is used to charge and discharge 30nF capacitors (39 Nos.) .

We have timing constraint here. We have to charge or discharge the capacitors within 15 us. 

In order to achieve, we have a half bridge driver circuit and it can be achieved through simulation.

The planned dissipative resistor is 50 ohms. The average current required is nearly 1A.

Due to dimension constraints, I can't do with this controller. I have to move to some other topology.

Here are my questions.

1) Based on the scenario explained, will LM5034 feasible for my application?

2) Is the half bridge circuit is the only option to achieve this speed (15 us)?

3) What will be the best isolated or non-isolated topology to fulfill my requirement?

4) Does this circuit needs 400W power to achieve my timing and dimensional requirements?

Kindly help me in this.

  • 0
    TI__Guru 73345 points

    Hi,

    I am not sure why you pick up LM5034 (not seem relevant to what you need). LM5034 is not a half-bridge controller.

    On your questions:

    1), No LM5034 is not a half bridge controller, and also not to relevant to your application

    2), Half bridge seems to me also not good to your applications.

    3), I suggest you to voltage step up with a push-pull converter in open loop, with UCC2808A-2, with a transformer to change 24V to 400V, then at 400V you can add your 15us charging / discharging circuit. You need to use a transformer to make voltage change from 24V to 400V. 

    4), If you need 1A from 400V, then it is a 400W in 15us. You do not have to design a 400W converter, you can add big capacitor at 400V before the 15us control switch. That big capacitor needs to store enough energy to provide 15us and 400W.

  • 0 in reply to Hong Huang
    Prodigy 60 points

    Hi,

             I understood that LM5034 is not feasible.  If I don't need 400W converter, how much power do I need?  What converter can be used? I'm planning to switch the voltages with a half bridge circuit. What is your view on it?

  • 0 in reply to Sivadharshan Kamaraj
    TI__Guru 73345 points

    Hi,

    It depends on how many 15us 400W delivery in 1 second, and the interval time between two 15us. You can calculate after your know these. Basically between two 15us 400W discharge, the output capacitors needed to be charged up ready to deliver 400W. So there will be a time for charging the output capacitors in a specified time to be ready before next 15us comes.