LT8410-1 Booster Circuit Current Draw

Hi,

I'd like to get some support regarding Linear's LT8410-1 boost converter. 

More specifically I am measuring a large disrepancy between simulated current consumption (using LTspice) and the reality of my circuit. 

To be more precise the boost converter is set to convert about 3.4V to 13.25V or 26.5V. I am measuring about 150uA current drawn from my supply in the first case and about 3mA in the second case. LTspice simulates an average current draw of ~130uA in the first case and about 250uA in the second case. 

The situation is a bit more complicated but I would like to discuss this in private if possible with one of the support engineers.

Thank you for any support.

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  • 0
    •  Analog Employees 
    on Jul 20, 2018 7:52 PM

    Hi, Garibaldi,

    The only evidence I have of this application working well is shown in the datasheet circuit, with lt8410. The included datasheet efficiency curve indicates the input current should be lower than 3.5mA with no load. We have not tested this circuit with the lt8410-1, and based on what I see from your bench test results it does not work well. Your bench test waveform indicates high ON time, and close to 1MHz switching frequency. It also indicates normal switching behavior, which implies to me the layout is probably not the issue.

    You indicate you want consumption to be lower, and I am saying you will get precisely that, if you copy the datasheet circuit as is.

    I will gladly offer additional assistance if you try the suggested lt8410 application and you find it does not work.

Reply
  • 0
    •  Analog Employees 
    on Jul 20, 2018 7:52 PM

    Hi, Garibaldi,

    The only evidence I have of this application working well is shown in the datasheet circuit, with lt8410. The included datasheet efficiency curve indicates the input current should be lower than 3.5mA with no load. We have not tested this circuit with the lt8410-1, and based on what I see from your bench test results it does not work well. Your bench test waveform indicates high ON time, and close to 1MHz switching frequency. It also indicates normal switching behavior, which implies to me the layout is probably not the issue.

    You indicate you want consumption to be lower, and I am saying you will get precisely that, if you copy the datasheet circuit as is.

    I will gladly offer additional assistance if you try the suggested lt8410 application and you find it does not work.

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