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  1. #1
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    Increase output voltage of a clk buffer

    Hello folks!
    I wanted to use the ICS551 clock driver to switch some drivers which are working in the range of 0-15V. The maximum working voltage of the ICS551 is 5V. So I need to do a voltage translation of the output to reach 15V. I have thinkin to use a Mosfet. However, I was not able to find one with similar switching characteristics as the ICS551. Any idea?
    On the other hand if someone knows a part like the ICS551(important the low propagation delay of this part) but with higher voltage range (up to 15V), please tell me. I have been getting crazy searching one...

    Thanks in advance

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    Re: Increase output voltage of a clk buffer

    Here a proposal for 12V & Tpd >3ns:
    http://www.ti.com/product/lmh7220



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    Re: Increase output voltage of a clk buffer

    Hi,

    It's quite unusual for a high speed logic to runs with 15V signal levels. What is it?

    As level shifter you may use a
    * high speed (Mosfet) driver
    * high speed comparator
    * high speed analog switch

    Klaus
    Please don´t contact me via PM, because there is no time to respond to them. No friend requests. Thank you.



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    Re: Increase output voltage of a clk buffer

    Hi!
    The TI comparator looks pretty interesting but I need 15V at high level.

    The application is to buffer the PWM of an IGBT dirver. I don't need high current because the dirver itself is powering the IGBT, however I need to control it with a custom PWM and it should a low or constant jitter. That is because I am trying to find something with very low tph, tpl and tpd (<5ns)...

    Thanks



  5. #5
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    Re: Increase output voltage of a clk buffer

    Please don't mix PropagationDelay, Jitter and Skew.
    Maybe you can describe a litte bit more about the application, and especially about the IGBT driver and the IGBT used.
    I still didn't get the need for the buffer. Or do you plan to drive multiple IGBTs, and have to increase fanout?



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    Re: Increase output voltage of a clk buffer

    Well I have to control three IGBT driver board with my prototype board. Every IGBT driver board is powered with +15V. And the control signals used to switch the IGBT top and the IGBT bottom are in the range of 0V-15V. The most important requirement of my prototype board is to avoid undesired short-circuit between three IGBT top or Three IGBT bottom. Because one top control signal from my prototype board drives three IGBTs top and one bottom signal from my prototype board drives three IGBTS bottom. Therefore the ideal requirement of the buffer placed between the FPGA and the IGBT driver board should be has a constant tph and tpl. But it is almost impossible to find one buffer with constant tph and tpl which works in the range of 0V-15V. So the minimum time requirements of tph and tpl should be less than 5ns for each one. I have thinking to use clock buffers because they have very low tph and tpl. However the maximum output voltage is 5V. And I need 15V. Any idea con increase it without losing speed?



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