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PGA460-Q1: To Use a long wire between transducer and the circuit

Chethan M
Prodigy 200 points
Part Number: PGA460-Q1
Other Parts Discussed in Thread: PGA460

If I use a wire of about 10 meters between the transducer and the PGA460 will I get the output? If yes,please suggest me how to do that. 

  • 0
    TI__Expert 4720 points
    Hi Chethan,

    Reading through section 10.1 "Layout Guidelines" in the PGA460 datasheet I do not believe that is recommend based on this exceprt:

    "The analog return path pins, INP and INN, are most susceptible to noise and therefore should be routed as
    short and directly to the transducer as possible. Ensure the INN capacitor is close to the pin to reduce the
    length of the ground wire"

    I believe you would be better off keeping the PGA460 as close to the transducer as possible and using power and communication lines for the 10 meter distance.

    Best regards,
    Blair
  • 0 in reply to Blair Conner
    Prodigy 200 points
    If it is not possible with PGA460 chip are there any other chips that can be used to increase the distance between the transducer and the circuit. As we have that requirement please suggest me any other driver chips other than PGA460 for driving the ultrasonic transducer.
  • 0 in reply to Chethan M
    TI__Mastermind 27950 points
    Hi Chethan,

    As Blair mentioned, it is not recommended, but it is still possible to use 10m cabling between the transducer and PGA460 IC. It is not a limitation of the device, but rather the low magnitude and sensitivity of the ultrasonic return data. Thus, we have no alternative IC to suggest. This is true for most systems that use Analog Front End amplification of a raw signal by several orders of magnitude in dB. Placing the sensor as close the AFE channel will yield the most optimal return path performance.

    To mitigate any antenna like effects which may couple and interfere with the ultrasonic return data, I recommend that you use shielded cabling. Also, if you are using a transformer based driver, you may want to consider a wide gauge wire to avoid driving losses due to wire resistance.

    The longer the cabling, the more at risk your long range performance becomes. I recommend that you experiment and compare the transducer performance when positioned immediately next to the PGA460 IC, versus when it is separated by 10m of wire. This experiment will help you quantify the SNR losses introduced by the extended cabling.