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I have recently purchased a LM2623 IC. I would like to use it for implementing a Boost regulator having the specs,

Input voltage - 1.2V

Input current - 0.16mA

 Output voltage - 13V

I would like to know how i can simulate using the IC and get a suitable schematic.Is there any simulation tool. I'm not able to find the component LM 2623 in Switcher Design Pro.

Please help.


  • LM2623 is similar to LM2621 except for the C3 capacitor selection.  You can use Webench to do the initial design using LM2621.  C3 value cannot be calculated.  You can only choose it by trial and error.

    John Tucker

    BSR-CCP LV/MV DC/DC Applications

  • Hello Adithya,

    Your boost design would require a 90% duty cycle at 100% efficiency. 

    D = (Vo - eff*Vi)/Vo.

    With reduction in efficiency, the duty cycle will increase and even with a 90% efficiency, the D would be 91%. The max operational duty cycle of the LM2623 is 90%. Therefore I believe this part might not be the best fit for your requirements.


  • In reply to Akshay Mehta:


    I'm developing an application called Hybrid Solar-Fuel cell off grid kit.

    I'll be using a solar cell to power a Hydogen Fuel cell which is then used to charge a 12 V rechargeable battery.

    The No Load Voltage of the solar cell is approximately 3 Volts. During solar-powered electrolysis, you can typically expect to generate approximately 1.7 Volts.

     The fuel cell has a No-Load Voltage of about 1.7 Volts and an Operating Voltage of about 0.9 V having a current in the range of 100 to 300 mA.

    So i need to boost 0.9 V,300mA to charge a 12V rechargeable battery.

    And its a standalone device having no auxillary supply. So the only supply is 0.9 V, 0.3A(300mA)

    Please do suggest me a suitable converter.