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High side MOSFET driver

Category: Hardware
Product Number: ADuM4135

I want to use ADuM4135 in my PCB. In my design I have a high voltage pulse generator which can output up to 2KV pulses (up to 2MHz). I want to connect/short the output of this generator with different electrical points. I am using series of MOSFET for my case. MOSFET will turn on before generator and stays on until generator stop output pulses. For driving MOSFETs I want to use ADuM4135 ICs (a single PCB may require over 40 ICs). 
Now, my question is, can I use ADuM4135 for my case, if yes, can you please provide some reference files.

Thanks.

  • Hi Saqi,

    Thank you for being in touch regarding your application. 
    I recommend to consider ADuM4146 instead as it is rated for VIORM = 2150 V peak, which is ideal to supports your voltage and speed requirements.

    Reference material can be found here:
    https://www.analog.com/en/products/adum4146.html#evaluation-kit

    Best regards,
    Luca  


  • Thanks for the response, I checked the reference design file, "https://www.analog.com/media/en/technical-documentation/user-guides/eval-adum4146-ug-2034.pdf" the schematic is page 4. I have a question, DESAT pin is connected to the input HV through a diode, can you explain this diode and DESET pin? Please, explain this point and what diode should I use, as it is not mentioned in the reference design BOM. 

    And part "ADUM4146A" is not available in Ltspice XVII.
    I saw some other high side driver from ADI, like, LTC7060, where for high side SW pin is directly connected to the MOSFET source pin (which for me makes sense). But in  ADuM4146 I can not understand the logic. How to use it as a high side driver, we do not need any input from MOSFET source pin? 

  • For this part I think, I got the logic. 
    The ADuM4135 is an isolated gate driver, which means it handles the gate driving through isolation rather than directly referencing the source pin of the MOSFET. This isolation is what allows it to manage high-side driving effectively without needing a direct connection to the MOSFET source pin.
    Correct me if I am wrong. 
    But I have a problem in simulation, check the attached file. 
    The output does not goes to zero. It switches from 400V to 374V. Please, check and point out my mistake. 
    Thanks

    1134.MOSFET_SWITCHING.asc

  • GND2 should be connected to the MOSFET, it is mentioned in the datasheet. "Ground Reference for Secondary Side. Connect the GND2 pin to the source of the SiC MOSFET being driven."
    I did that in my simulation but now result is strange, please check the .asc file.
    3857.MOSFET_SWITCHING.asc

  • Hi,

    ADuM4146A model is available in the latest version of LTspice including an example circuit, please update your LTSpice software to access the latest library. 

    Best regards,
    Luca

  • Thanks for the response, which Ltspice version are you using? It looks different for me, I am using Ltspice XVII.

  • I'm using the latest LTSpice release.
    Ltspice XVII is no longer supported. I recommend to download the new improved LTspice simulator.

    You can download the latest software release here:

    https://www.analog.com/en/resources/design-tools-and-calculators/ltspice-simulator.html

    Best regards,
    Luca

  • The example provided in the Ltspice is for low side MOSFET driver and also there is no explanation. Please, check the .asc file which I provided. I want to use ADuM4146A as a high side MOSFET driver. What I want is, where should I connect my MOSFET source pin? 
    Before going to PCB design I want to confirm the output in simulation. I upload the file from the example folder of Ltspice, can you update it for high side MOSFET driver, I tried but the result is different. 
    ADuM4146A.asc

  • I need assistance with modifying the LTspice simulation for the ADuM4146A isolated gate driver to correctly drive a high-side MOSFET. I have followed the datasheet's recommendation to connect GND2 to the source of the MOSFET to provide the necessary reference for high-side driving. Despite these modifications, the simulation is not producing the expected results.

    Context:

    • Application: Driving a high-side MOSFET to handle HV pulses. Pulses are bipolar. As I mentioned in my initial comment, I have a generator which produces HV pulses. I want to switch these pulses to different electrodes. My switches will be on the high side. MOSFET will stays on until generator stop producing pulses. 
    • Current Status: Using the example file provided by ADI for low-side configuration, modified for high-side operation by connecting GND2 to the MOSFET source. Mentioned in the datasheet of ADuM4146 page 9 " Ground Reference for Secondary Side. Connect the GND2 pin to the source of the SiC MOSFET being driven". 
    • Issue: The output voltage behaviour is strange, output should be same as input, which is not. 

    Request:

    Could you please provide guidance or an updated LTspice simulation file that accurately reflects a high-side configuration using the ADuM4146A for HV pulses? Any specific steps or corrections to achieve the correct operation would be greatly appreciated.
    Please, change the file and make it compatible for high side. You can use 100V DC on MOSFET drain. I tried but I am not able to get any result.
    I need it urgent, I have to finalize my schematic. 

    0675.ADuM4146A.asc

  • Am I getting any answer or not? If not, please just leave a comment.