Driving Transducer in Ltspice


I was trying to drive this transducer in the image (with H-bridge and LC filter circuits behind it). However, after simulating the whole circuit, the running began and continued very long time and simulation gave meaningless plot. How can I solve this problem? Because of the company policy I can not share the whole circuit. Also, input of the transducer is 250-300 Vpeak with 0V offset. And load resistance, which corresponds resistance of transducer, must be approximately 50ohms. In other words, transducer is load and has 50 ohms resistance. Also, values of the components are not exactly the same as with the real circuit, because of company policy I changed them.


Thank you for your consideration

  • 0
    •  Analog Employees 
    on Sep 28, 2021 10:35 AM

    Hi Efe,

    Good day. As much as we want to help you, I'm afraid we need more information of your application circuit so that we can get a complete view of your problem. several factors can affect simulation time. Some are frequency related. others are cause by convergence issues which can be created by a number of ways. Unless we can see the complete picture we can't provide the best solution of your problem.

    Regards,

    PaulDaria

  • Hi PaulaDaria,

    Thank you for your support firstly. I put the whole circuit as you wanted. I tried to simulate by connecting 50 ohm resistor, representing transducer. It worked well. But, when I connected transducer at the end (by removing 50 ohm of course), I got meaningless simulation result. You can try as well in Ltspice.

    Thank you in advance
    1374.Draft1.asc

  • 0
    •  Analog Employees 
    on Sep 30, 2021 12:53 AM in reply to Efe

    Hi Efe,

    I checked your schematics, and I found nothing unusual. However when I run your circuit the voltages across Leg_out1 and 2 are quite so high, reaching to some kV. I am not sure how a GaN behaves exactly but I just added a parallel diode on all for GaNs just to make sure the the current between Leg_out 1 and 2 are always continuous, knowing that is mostly inductor and inductor hates getting cut off else it will generate very voltage spikes. I mange to run your simulation by doing this.

    I'm not sure though if this is what you want to achieve. see below solution.

    Thanks.