Hello, Analog Devices,
My system has next structure:
CAM(SMX-F30BP) -> Galvanic Transformer 1 -> (ADV7180BCPZ) -> ADV212 -> MY DATA CHANNEL -> ADV212 -> ADV7391BCPZ -> Galvanic transformer 2 -> TV
When I direct my camera to bright light source (for examp, lamp), TV shows blinking picture (sometimes picture dissapears).
To catch this effect the camera shoud be directed to the upper left corner, or to the lower right ones. When I delete galvanic transformer 1 from the system, picture doesn't blinking.
Simple system CAM -> Galvanic Transformer -> TV works stable.
The camera output video stream in PAL 720x576(50i) format. CVBS to Ain1.
I use following settings for the chip:
|Register Name||Register number (in hex)||Register Value (in hex)|
|Extended output control||04||24 (00100100)|
|Analog clamp control||14||12 (00010010)|
|Digital clamp control1||15||60 (01100000)|
|Shapping filter control||17||41|
|Shapping filter control2||18||93 (10010011)|
|Default Value Y||0C||52 (01010010)|
|Default Value C||0D||F8 (11111000)|
|Misc gain control||2B||A0|
|VS field control||31||02|
|AGC mode control||2C||AE (10101110)|
|Chroma gain control1||2D||F4 (11110100)|
|Chroma gain control2||2E||00|
|Luma gain control1||2F||F2 (11110010)|
|Luma gain control2||30||00|
|IF comp control||F9||07 (00000111)|
|VS field pin control||58||01|
|Manual window control||3D||A2 (10100010)|
|CTI DNR control1||4D||CF (11001111)|
|CTI DNR control2||4E||0A|
|CTI DNR control4||50||0A|
|Lock count||51||F6 (11110110)|
|PAL V begin||E8||41|
|PAL V end||E9||84|
|VBLANK control1||EB||6C (01011100)|
|VBLANK control2||EC||6C (01011100)|
|Peaking control||FB||A0 (10000000)|
|Coring threshold||FC||04 (00000100)|
|Register map hidden||0E||80|
|Register map user||0E||00|
I have made 2 situation (good case and bad case):
In good case picture from DAC was stable and we could measure normal clamp level from it (600 mV). (Fig. 28 from Datasheet). Photos are in attachement.
In bad case picture from DAC was blinking and we could see how clamp level have changed. ClampLevelDelta = 30-40 mV. Clamping system were inefficient.
May I change the power of current sources in ADV7180 clamp system? Will it help me solve this problem?
Thanks in advance.