參數(shù)資料
型號: TVP5150PBS
廠商: TEXAS INSTRUMENTS INC
元件分類: 顏色信號轉(zhuǎn)換
英文描述: COLOR SIGNAL DECODER, PQFP32
封裝: PLASTIC, TQFP-32
文件頁數(shù): 5/68頁
文件大?。?/td> 917K
代理商: TVP5150PBS
Functional Description
7
May 2006
SLES043A
3
Functional Description
3.1
Input Multiplexers and Buffers
The TVP5150 device has an analog input channel that accepts two video inputs, ac-coupled through 0.1-
F
to 1-
F capacitors. The two analog input ports can be connected as follows:
Two selectable composite video inputs or
One S-video input
The internal video multiplexers can be configured via I2C. The internal nodes are grounded for zero channel
crosstalk. The input buffers are continuous time amplifiers that allow an input range of up to 0.75 VPP. This
allows the decoder to support input ranges of 0 to 1.5 V with an external attenuation of one-half.
3.2
Clamp
An internal clamping circuit restores the ac-coupled video signal to a fixed dc level. The clamping circuit
provides line-by-line restoration of the video sync level to a fixed dc reference voltage. Two modes of clamping
are provided, coarse and fine.
In coarse mode, the most negative portion of the input signal (typically the sync tip) is clamped to a fixed
dc level and remains on. This mode is used while the timing processor is searching for the horizontal sync.
Fine clamp mode is enabled after the horizontal lock is achieved. This is enabled to prevent spurious level
shifting caused by noise more negative than the sync tip on the input signal. If fine clamp mode is selected,
then clamping is only enabled during the sync period.
When in bottom level mode, the sync tip of the input signal is set to output code 0 of the A/D converter
(ADC).
When in mid-level mode, fine clamp restores the dc level of the signal to the mid-range of the ADC.
S-video requires the fine clamp mode on the chroma channel for proper operation. The clamp can be
completely disabled using software registers.
3.3
Programmable Gain Amplifier and Automatic Gain Control Circuit
The programmable gain amplifier (PGA) and the automatic gain control (AGC) circuit work together to make
sure that the input signal is amplified sufficiently to ensure the proper input range for the ADC. The gain is
controlled by a 4-bit gain code.
Input video signal amplitude can vary significantly from the nominal level of 1 VPP (140 IRE). An AGC circuit
adjusts the signal amplitude to utilize the maximum range of the A/D converter without clipping. The AGC
adjusts the gain to achieve the desired sync amplitude. The PGA has a range of 0 to 12 dB.
3.4
A/D Converter
The ADC has 9 bits of resolution and runs at a maximum speed of 27 MHz. The clock input for the ADC comes
from the PLL. The data is aligned to the pixel clock supplied from the PLL and matched in delay. The ADC uses
the REFM and REFP terminals as the internal reference generator. For configuration of these terminals,
please refer to Figure 51.
3.5
Composite Processing Block Diagram
The composite processing block process NTSC/PAL signals into the YCbCr color space. Figure 31 explains
the basic architecture of this processing block.
Figure 31 illustrates the luminance/chrominance (Y/C) separation process in the TVP5150 device. The
composite video is multiplied by subcarrier signals in the quadrature modulator to generate color difference
signals U and V. U and V are then low-pass filtered to achieve the desired bandwidth and to reduce crosstalk,
by the color low-pass filters.
相關(guān)PDF資料
PDF描述
TVP5150PBSR COLOR SIGNAL DECODER, PQFP32
TVP5151IPBSQ1 COLOR SIGNAL DECODER, PQFP32
TVP5151IPBSRQ1 COLOR SIGNAL DECODER, PQFP32
TVP5151IPBSR COLOR SIGNAL DECODER, PQFP32
TVP5151IPBS COLOR SIGNAL DECODER, PQFP32
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TVP5150PBS 制造商:Texas Instruments 功能描述:IC DECODER VIDEO SMD
TVP5150PBSG4 功能描述:視頻 IC VERY LOW POWER VIDEO DECODER RoHS:否 制造商:Fairchild Semiconductor 工作電源電壓:5 V 電源電流:80 mA 最大工作溫度:+ 85 C 封裝 / 箱體:TSSOP-28 封裝:Reel
TVP5150PBSR 功能描述:視頻 IC Very Low Power Video Decoder RoHS:否 制造商:Fairchild Semiconductor 工作電源電壓:5 V 電源電流:80 mA 最大工作溫度:+ 85 C 封裝 / 箱體:TSSOP-28 封裝:Reel
TVP5150PBSRG4 制造商:Texas Instruments 功能描述:
TVP5151 制造商:TI 制造商全稱:Texas Instruments 功能描述:Ultralow-Power NTSC/PAL/SECAM Video Decoder