Post Go back to editing

ADV 3201 Input Voltage level

Hi,

I read from datasheet that the maximum delta for video input is -0,8 to 1V but that the minimum voltage is -0,75/+0.75, this is not clear to me.

I have an Video signal output from ADV8005 that is 0 to 1V. Below my questions:


1) If I enter directely into adv3201 the ADV8005 output (with 300Ohm termination), this can be a problem?


2) If I use Vclamp (with Vref set to 0 and so Vclamp set internally to -300mV) and an AC coupling ingress, the video input is traslated to level -300mV to 700mV or the clamping is used only to stop the negative excursion and so the video is not traslate but only limited?


3) did you have any suggest in how we can link the output from ADV8005 to ADV3201?

NOTE: We will use +-3V3 to supply the device.

regards,

Dario

Parents
  • Hi,

    Try altering the Vref of the ADV8005 or AC couple it to the input of  ADV3201.

    Regards,
    Goz

  • Hi Gauzz,

    So if I use the -3V3/+3V3 supply I can AC couple the signal and I should have the "classic" video signal (-300mV to +700mV). And this should be fine, right?

    Instead if I use the 5V supply I can go directely with the 0 +1V Video signal without AC coupling and at the output of the ADV3201 I should have the same signal but with gain 2 (0 up to 2V), right?

    regards,

    Dario

  • Hi Dario,

    So if I use the -3V3/+3V3 supply I can AC couple the signal and I should have the "classic" video signal (-300mV to +700mV). And this should be fine, right?

    Yes, you are correct.

    Instead if I use the 5V supply I can go directely with the 0 +1V Video signal without AC coupling and at the output of the ADV3201 I should have the same signal but with gain 2 (0 up to 2V), right?

    No, adjusting it to a single supply configuration will also move the input voltage range.

    ADV3201 is only specified at +3.3V I'll use this as example. Currently at that supply range ADV3201 only accepts voltages -0.75 to 0.75V. Meaning it only accepts voltages 2.55V away from the rails. Moving it to a single supply configuration at 6.6V to GND, you new input voltage range will be 2.55V to 4.05V.

    Regards,
    Goz

Reply
  • Hi Dario,

    So if I use the -3V3/+3V3 supply I can AC couple the signal and I should have the "classic" video signal (-300mV to +700mV). And this should be fine, right?

    Yes, you are correct.

    Instead if I use the 5V supply I can go directely with the 0 +1V Video signal without AC coupling and at the output of the ADV3201 I should have the same signal but with gain 2 (0 up to 2V), right?

    No, adjusting it to a single supply configuration will also move the input voltage range.

    ADV3201 is only specified at +3.3V I'll use this as example. Currently at that supply range ADV3201 only accepts voltages -0.75 to 0.75V. Meaning it only accepts voltages 2.55V away from the rails. Moving it to a single supply configuration at 6.6V to GND, you new input voltage range will be 2.55V to 4.05V.

    Regards,
    Goz

Children
No Data