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Original question:

AMC3301: Can AMC3301 detect 10us pulse voltage?

AMC3330: AMC3330

Shawn Xiang
Prodigy 10 points
Part Number: AMC3330
Other Parts Discussed in Thread: AMC3336

Dear expert,

     We have a voltage signal of 460KHz, is AMC3330 fit for it's voltage detection?

     From Amc3330 datasheet, the output bandwidth is 375KHz, seems this chip couldn't support 460KHz voltage signal detection.

     But in the datasheet also mentioned: the internal TRx carrier is 480MHz as below. It's much more higher than 460KHz. Does this 375KHz limitation come from the amplifier stage ( It seems the Isolation stage could support more than 460KHz )?

7.3.2 Isolation Channel Signal Transmission

The AMC3330 uses an on-off keying (OOK) modulation scheme to transmit the modulator output-bitstream

across the capacitive SiO2-based isolation barrier. Fig 7-1 shows the block diagram of an isolation channel. The

transmitter modulates the bitstream at TX IN with an internally generated, 480-MHz carrier and sends a burst

across the isolation barrier to represent a digital one and sends a no signal to represent the digital zero. The

receiver demodulates the signal after advanced signal conditioning and produces the output. The symmetrical

design of each isolation channel improves the common-mode .....

BR&Thanks

Shawn

  • 0
    TI__Expert 5875 points

    Hi Shawn,

    Thank you for your question.

    The 480MHz is an internal signal generated to transmit the modulator bitstream across the isolation barrier. This is separate from the output bandwidth. Since the AMC3330's output bandwidth is 375 KHz, this is the frequency the device can measure up to. So, a 460KHz signal on the output would not be within these specifications.

    Please let me know if you have more questions on this device!

    Best regards,
    Eva

  • 0
    TI__Guru 51101 points

    Hi Shawn,

    The bandwidth is set by the integrated digital filter after the isolation barrier. The device would be able to detect a 460kHz signal, but it would be attenuated as shown by figure 6-9 and also be impacted by the propagation delay time of approximately 3uS. 

    How accurately and how quickly do you need to sense this signal? 

    What type of application are you working on? 

  • 0 in reply to Alexander Smith
    Prodigy 10 points

    Hi，Alexander & Eva

         Many thanks to your warmly support.

         We are working for a medical device (RF ablation) development.

         We hope we can sense this signal once per 5ms, with the accuracy of 0.1%.

         Could you please help recommend another chip solution? Or is AMC3336 a feasible option?

    BR&Thanks

    Shawn

  • 0 in reply to Shawn Xiang
    TI__Expert 5875 points

    Hi Shawn,

    An accuracy of 0.1% at 200 Hz for this device is going to be difficult to achieve. I would recommend looking for a device that is 16 bits or more and a higher input signal frequency. You can use this tool to find a device that meets your specifications. Hope this helps!

    Best regards,

    Eva