ADV7180 Video Input Signal Range

Hi,

 Please find the below response for your query,

1. What is the tolerance for the maximum input voltage? I would like to know the specific value and percentage.

     ADV7182 the maximum input voltage AVDD = DVDD = PVDD = 1.8V and DVDDIO = 1.8V or 3.3V with a 5% tolerance.

    Digital input would max = 3.3V + 0.3V = 3.6V with 5% tolerance.

    ADV7180, the typical input voltage range for CVBS video input is:

        AC-coupled, centered at 0.5 V (nominal).

Typical peak-to-peak voltage: 1 Vpp (standard NTSC or PAL video level).

Maximum allowable signal amplitude (before clipping or issues): about 1.0 Vpp ±10%.

Thus, maximum safe peak-to-peak input is ~1.1 Vpp.

In voltage terms:

Sync tip (lowest point): around 0 V (After AC coupling and Internal biasing).
White peak (highest point): around 1 V.
If we take 10% as tolerance:  
1.0 Vpp + 10% = 1.1 Vpp max allowed.
Percentage tolerance = ±10%.

Also kindly refer this thread  RE: Digital Inputs logic "1" voltage is higher than DVDDIO and digital input logic "0" voltage is lower than 0V on ADV7182&ADV7182A digital input pins 

2. What will happen to the image if the maximum input voltage including the tolerance is exceeded ?

  Kindly note that, Applying a voltage beyond these ratings or operating outside of temperature limits can cause permanent deterioration or destruction of the device.
These absolute maximum voltages are determined by the silicon process (e.g., gate oxide thickness and transistor handling capability).
In the ADV7180, the absolute maximum input voltage for analog video inputs is approximately AVDD + 0.3 V (around 2.1 V if AVDD = 1.8 V).
The typical CVBS video input signal is approximately 1 V_p-p, which is well below this limit. Exceeding the absolute maximum even briefly can result in internal damage (such as clamp diode breakdown or ADC damage), leading to loss of sync, image distortion, or complete chip failure.
For digital inputs and outputs, VOH and VOL levels depend on the DVDDIO supply voltage, as listed in Table 1 of the datasheet. Proper matching of DVDDIO is necessary to maintain valid logic levels, but this is separate from the analog input voltage tolerance.
In the case of analog CVBS video input to ADV7180, exceeding the absolute maximum (about 2.1V) can damage internal clamping circuits or ADC inputs.
Possible permanent internal damage to input structures (e.g., clamp diodes break down)
May cause:
  No image (decoder cannot lock sync)
  Image noise, color distortion
  Sync loss (rolling screen, black screen)
 Chip failure (short circuits, latch-up)

Thanks,

Poornima