AKM 公司的AK8853是NTSC, PAL和SECAM数字视频解码器,输出信号是和ITU-R BT.601兼容的YCbCr格式. AK8853具有四路输入通路,内部有视频开关和PGA以及自适应的自动增益控制(AGC).本文介绍了AK8853的主要特性,方框图以及典型的应用框图.

AK8853XQ/ VN NTSC/PAL/SECAM Digital Video Decoder
The AK8853 is a single-chip digital decoder for NTSC, PAL, and SECAM composite video signals. Its output data is in YCbCr format, compliant with ITU-R BT.601. Its pixel clock, with a generated clock rate of 27 MHz, synchronizes with the input signal. Its output interface is ITU-R BT.656 compliant. Closed-caption, VBID, and WSS encoded information in the input signal is externally accessible. Microprocessor access is via a I2C interface.

主要特性:
Decodes composite video signals NTSC (J, M, 4.43), PAL (B, D, G, H, I, M, N, Nc, 60), SECAM.
Four input channels, with internal video switch.
10-bit ADC 1 channel.
Internal line-locked and frame-locked PLLs for generation of clock synchronized with input signal.
Internal PGA (-6 dB to 6 dB).
Adaptive automatic gain control (AGC).
Auto color control (ACC).
Image adjustment (contrast, saturation, brightness, hue, sharpness).
Automatic input signal detection.
Adaptive 2-D Y/C separation.
PAL decoding phase correction.
ITU-R BT.656 format output (with 4:2:2_8 bit parallel_EAV/SAV)
Closed-caption signal decoding (output via register).
WSS signal decoding (output via register).
Macrovision signal detection (Macrovision certification).
Power down function.
I2C control.
1.70~2.00 V core power supply.
1.70~3.60 V interface power supply.
Operating temperature range: −40°C to 105°C. (AK8853XQ)
Operating temperature range: −40°C to 85°C. (AK8853VN)
48-pin LQFP package. (AK8853XQ)
48-pin QFN package. (AK8853VN)



图1. AK8853方框图



图2. AK8853应用方框图

来源：AKM