AK8851 Datasheet, PDF (14/80 Pages) Asahi Kasei Microsystems – NTSC/PAL/SECAM Digital Video Decoder

ASAHI KASEI
(8) Y/C Separation Function
[AK8851]
For NTSC,NTSC-4.43 signal inputs :
Adaptive Y/C separation is used. It is also possible to lock this function to either 3-line 2 dimensional Y/C separation, or
primary dimensional (BPF) Y/C separation.
For PAL-B,D,G,H,I,M,N,Nc,NTSC-4.43,PAL 60 signal inputs :
Adaptive Y/C separation is used. It is also possible to lock this function to either 5-line 2 dimensional Y/C separation, or
primary dimensional (BPF) Y/C separation.
For SECAM signal input :
Only the primary dimensional (BPF) Y/C separation is effective (even if the adaptive type is set, primary Y/C separation is
performed).
(9) input signal synchronization
The AK8851 automatically synchronize the incoming input signal when the input signal is switched or when the number of
lines in a Frame changes (VLOCK function).
(10) Output Signal Bandwidth
Luminance Signal Bandwidth : DC ~ 5.5 MHz - 0.5 dB ( DC ~ 5MHz +/- 0.1 dB ripple )
The luminance bandwidth is selectable among 3 ranges via a register setting.
Chroma Signal Bandwidth : 750 KHz ~ 1.5 MHz ( -3 dB ) ( 2 ranges selectable )
(11) Video Image Quality Control Function
Contrast, Brightness, HUE, Saturation levels and Sharpness level are adjustable.
* HUE and Color Saturation levels are not adjustable when using SECAM signals.
(12) Output Interface
• ITU-R BT.601 compatible signal output levels ( with Limit On/Off function)
• Decoded data output is ITU-R BT.656 format (depending on the input signal quality).
• Enables to detect only those signals which are valid during Active Video period ( 720 pixels ), by HSYNC/VSYNC
( FIELD )/ DVALID signals.
• 8-Bit output form at 27 MHz rate or 16-Bit output form at 13.5 MHz rate (selectable by register ).
(13) Other Functions
• Black level signal is output in self-operating mode when no signal is applied (Y = 16Cb,Cr = 128). It is also possible to
output Blue level (register selectable).
• Dedicated output pin for no-signal-input detection
• I2C Bus Host Interface ( 400 KHz )
• Power Down mode
• Decoding Function for Closed Caption, VBID (CGMS-A) and WSS signals.
CRCC that is added to CGMS-A is decoded by the AK8851.
( note ) In this data sheet, Sync level and Burst level of the NTSC signals are also converted and expressed in [mV],
not in [IRE].
MS0244-E-03
14
Confidential
2005 / 07