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TPS43061: Suitable for Driving LMG5200?

Part Number: TPS43061
Other Parts Discussed in Thread: LMG5200,

I've been looking around for a synchronous boost control IC that might be suitable for driving the LMG5200, and it seems like the TPS43061 might be a good fit. My overall specifications for the boost converter are:

5-9V input (2x LiIon cells)

15V output @ 3A

Issues I've run into with other controllers:

  • UVLO voltage too high on common PWM control ICs (UCx84x) - Not a problem with TPS43061
  • Control algorithms which use the SW pin on the controller - Since the LMG5200 has ground-referenced inputs on both LO and HI, the controller SW pin would need to be tied to ground. The TPS43061 does mention adaptive dead-time control in the datasheet. Is it okay to ground the SW pin?
  • DCM detection - This looks like it will work well, since the current sensing is not switch current, but inductor current.
  • Gate Drive voltage - The LMG5200 has a higher AbsMax input voltage than some other GaN half-bridge modules I have considered, so the 5.5V output of the TPS43061 shouldn't be a problem.

Are there any other concerns with using the TPS43061? I am working on a schematic now, and should be able to share it tomorrow.

Thanks in advance!

Paul

  • Hi, Paul,

    MG5200 has ground-referenced inputs on both LO and HI, both of them are limited to +12V absolute maximum rating. 

    Please send your schematic for review.

    Thank you

    Zhiyang

  • Thanks Zhiyang! I have two follow-up questions. First, are there any synchronous Boost converters that would be suitable for use with GaN Half Bridge modules?

    I am also interested in learning more about why tying the SW pin on the controller to ground instead of the half-bridge switched node could cause damage? Are you stating that it could damage the controller, or is the concern that it could cause damage to the larger circuit? I can't see a way that the TPS43061 would be damaged... The internal bootstrap diode would never be reversed biased, but that shouldn't be an issue. If the adaptive deadtime control is disabled, it might be necessary to add a basic dead-time delay circuit between the TPS43061 and the LMG5200, but it seems this is common on GaN devices. The datasheet seems to indicated that 65-75ns will be the expected delay time on the TPS43061, and the LMG5200 is spec is <50ns from input-to-switch.

    Is there another concern with trying the control SW pin to ground than the two I've identified above?

    Thanks,

    Paul

  • Hi, Paul,

    Could you send your schematic for review?

    Thanks

    Zhiyang