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TRF37C75: TRF37C75 DC Bias Reduction

Hayden_Hast
Intellectual 1515 points
Part Number: TRF37C75
Other Parts Discussed in Thread: TRF37C73

Hi Team,

I'm considering the TRF37C75 for a 1.3GHz radio PA replacement. Very impressed with the TRF37C75 performance. However, it's a little power hungry.

Is it possible to reduce the voltage on the Active Bias Supply (pin 1) in order to lower the supply current? I would keep the typical Vcc (4-5V) on the RFout pin.

Thanks,

Hayden

  • 0
    TI__Genius 15975 points

    Hi Hayden,

    Glad that you liked the TRF37C75 performance. How low of a supply voltage on the Active Bias Supply (pin 1) are you planning to go? I would not recommend going below the recommended operating supply voltage of 4.5V, as the device is not tested beyond this value. The datasheet parameters may not hold across parts going beyond the recommended operating conditions.

    Best Regards,

    Rohit

  • 0 in reply to Rohit Bhat
    TI__Intellectual 1515 points

    Rohit,

    From the testing (attached chart), it looks like the device meets the 15dB power requirements with 3-3.5 Vdc.

    I guess a better question would be, if the device were to be run at 3.5V DC bias, is there any known behavior we should expect? Such as certain functions that require an absolute Vmin to boot up? (keeping in mind you don't test the device below 5V and nothing is guaranteedTRF_Data.docx)

    Regards,
    Hayden

  • 0 in reply to Hayden_Hast
    TI__Genius 15975 points

    Hayden,

    At this point, I think there is no known anomaly or behavior if the device were to be run at 3.5V DC bias. I would not recommend going lower than 3V as you have noted in your measurement, the RF output power reduces drastically below that. However, I wanted to re-iterate that the parts are not tested below the recommended operating supply of 4.5V and any un-expected behavior is something you would have to take care in operating the device outside its recommended operating range.

    Have you looked at the TRF37C73 for your application? I think this device should fit nicely for what you are trying to achieve with 3.3V supply and 16.5dBm of RF output power. 

  • 0 in reply to Rohit Bhat
    TI__Intellectual 1515 points

    Thanks for the clarification (noted that operating below 4.5V is not recommended and operation isn't guaranteed) and the recommendation. The TRF37C37 actually looks like a better fit here. Much appreciated.

    -Hayden