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DRV135: Power Supply Recommendations

Part Number: DRV135
Other Parts Discussed in Thread: OPA1637

Hi everyone,

I want to know what value is the best to operated the DRV135 . I have an audio signal generated by microcontroller where it operate with 5V. Since output microcontroller is single end, I place a DRV135 to convert differential output. The main input voltage supply is 24VDC, Could you recommend any DC-DC converter to supply DRV135?

Thanks.

  • Hi Samuel,

    The electrical characteristics of DRV135 were specified with Vs=+/-18V, so the +/-18V split supply is the most recommendable.

    While, I'm not sure the recommendable power solution to create +/-18V from 24VDC.
    In my understanding, it may be constructed with a buck convertor and its inverting buck-boost configuration.
    Could you please post your inquiry for the power solution onto power E2E forum?

    Best regards,
    Iwata Etsuji

  • Hi Iwata,

    If the audio generated by microcontrolles is 5Vpeak, What should be the minimum voltage supply for DRV135?   

    Thanks

  • Hi Iwata,

    Additional, As per I see DVR135 consist of opamps , I want to know if amplifiers offer a rail-to-rail output

    Thanks

  • Hi Samuel,

    At first, I would like to confirm the signal source from the microcontroller.

    If it is 5Vpeak to peak signal, the attached schematic is an example of use-case for DRV135.

    DRV135_SEDE.TSC

    However, as you pointed out, DRV135 doesn't have rail-to-rail output, so there is a risk of clipping even if +/-5V supply condition.

    While, what is your expected output? Is it ground common differential output or Vs/2-common mode output is acceptable?  i.e. 2.5V common for 5V single supply?

    If you can accept any output common mode voltage and less drivability(output current) , how about OPA1637?
    Indeed, OPA1637 needs at least 4 external resistors, but it has more flexibility than DRV135.

    Thank you and Best regards,
    Iwata Etsuji

  • Hi Iwata,

    Output signal from the microcontroller is a square wave, then it is filtered and converted into balanced signal. Balanced signal is transmitted over long cable. The signal at the end of the cable is connected to a professional amplifier equipment.

    Could I use +/-15VDC isolated DC-DC converter? Is there problem with respect reference voltage of 5V power supply and reference voltage of +/-15V isolated DC-DC converter?

    Thanks

  • Hi Samuel,

    The isolated +/-15V dc supply basically works well for your usage.
    However, I have a little concern about its regulation performance and your expected loading current.
    If there is no problem on it, it should work well.

    Best regards,
    Iwata Etsuji

  • Hi Iwata,

    If I use isolated DC-DC converter with output +/-15V @ 33mA, I have to use digital isolator in order to reference input signal of DRV135 and local ground,  Is correct?

    Best Regards

  • Hi Samuel,

    It's not necessary to use digital isolators. 
    You need to put a DC-blocking cap on the front of DRV135 since DRV135 can only accept ground common signal.

    Best regards,
    Iwata Etsuji