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converting high speed 5V clock to -5V

Hi

I want to convert high speed (500 MHz) 5V clock to -5V. I wonder if ADG3248 is suitable in terms of voltage level. If not, which part is proper instead?

Thanks

Mohammad

  • Hi Mohammad,

    Unfortunately, the ADG3248 does not cover this wide range and negative level translation.

     

    I would think the level translation you need can be catered by using operational amplifiers.

     

    Best Regards,

    May

  • Hi,

    I'm moving this question to the amplifiers community to better support the application.

    Best Regards,

    May

  • Hi,

    We are looking into this, we'll get back to you with the part you need.

    Regards,
    Goz

  • Hi Mohammad,

    The combination of frequency and voltage requirement is relatively high for a single chip solution. I had explore the option to use comparator or an opamp to achieve this, however there are tradeoff seen on both product. Comparator is limited supply while opamp is limited by slew rate, which would require at least 10000V/uSec to toggle a -5v at 500MHz, for a +/-5v supply.

    One option which I think worth looking uses a comparator, possibly AD8465 as a driver then the output of the comparator drives a switch that will connect and disconnect a -5v supply at the output. One side of the switch is connected to the -5v supply and the other side is where you can get your output from, this pin should also have a resistor connected to ground so once the switch turns off this will pull the line to ground. The main challenge with this design is the switch should be fast enough to toggle at 500Mhz.

    Can you please share a target application of such requirement?

    Regards,

    Joven

  • Hi Joven,

    Actually I want to drive a high speed GaAs RF switch (HMC347ALP3E). The proposed driver in the datasheet is quite low speed, so I'm looking for another solution.

    The AD8465 is quite fast. Is it possible to generate -5 and 0 levels from 0 and 3.3V clock?

    Regards

    Mohammad

  • Hello Mohammad,

    Looking at the HMC347ALP3E specs, the typical ton and toff is 10nSec, this means that the typical on-off cycle is around 20nSec or 50MHz. Switching frequency of 500Mhz is relatively high for HMC347ALP3E.

    Can you please confirm you intended switching frequency on your application? and is it possible to share more information about your intended application of HMC347ALP3E.

    Regards,

    Joven