Functional Description

Up to 10 selectable individual composite video inputs

Up to four selectable S-video inputs

Up to three selectable analog YPbPr video inputs and one CVBS input

Up to two selectable analog YPbPr video inputs, two S-video inputs, and two CVBS inputs

The input selection is performed by the input select register at I2C subaddress 00h (see Section 2.11.1).

2.1.2 Analog Input Clamping

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. The selection between bottom and mid clamp is performed automatically by the TVP5147M1 decoder.

2.1.3 Automatic Gain Control

The TVP5147M1 decoder uses two programmable gain amplifiers (PGAs), one per channel. The PGA can scale a signal with a voltage-input compliance of 0.5-VPPto 2.0-VPPto a full-scale 10-bit A/D output code range. A 4-bit code sets the coarse gain with individual adjustment per channel. Minimum gain corresponds to a code 0x0 (2.0-VPPfull-scale input, −6-dB gain) while maximum gain corresponds to code 0xF (0.5 V PP full scale, +6-dB gain). The TVP5147M1 decoder also has 12-bit fine gain controls for each channel and applies independently to coarse gain controls. For composite video, the input video signal amplitude can vary significantly from the nominal level of 1 VPP. The TVP5147M1 decoder can adjust its PGA setting automatically: an automatic gain control (AGC) can be enabled and can adjust the signal amplitude such that the maximum range of the ADC is reached without clipping. Some nonstandard video signals contain peak white levels that saturate the ADC. In these cases, the AGC automatically cuts back gain to avoid clipping. If the AGC is on, then the TVP5147M1 decoder can read the gain currently being used.

The TVP5147M1 AGC comprises the front-end AGC before Y/C separation and the back-end AGC after Y/C separation. The back-end AGC restores the optimum system gain whenever an amplitude reference such as the composite peak (which is only relevant before Y/C separation) forces the front-end AGC to set the gain too low. The front-end and back-end AGC algorithms can use up to four amplitude references: sync height, color burst amplitude, composite peak, and luma peak.

The specific amplitude references being used by the front-end and back-end AGC algorithms can be independently controlled using the AGC white peak processing register located at subaddress 74h. The TVP5147M1 gain increment speed and gain increment delay can be controlled using the AGC increment speed register located at subaddress 78h and the AGC increment delay register located at subaddress 79h.

2.1.4 Analog Video Output

One of the analog input signals is available at the analog video output terminal, which is shared with input selected by I2C registers. The signal at this terminal must be buffered by a source follower. The nominal output voltage is 2 V p-p, thus the signal can be used to drive a 75-line. The magnitude is maintained with an AGC in 16 steps controlled by the TVP5147M1 decoder. In order to use this function, terminal VI_1_A must be set as an output terminal. The input mode selection register also selects an active analog output signal.

2.1.5 A/D Converters

All ADCs have a resolution of 10 bits and can operate up to 30 MSPS. All A/D channels receive an identical clock from the on-chip phase-locked loop (PLL) at a frequency between 24 MHz and 30 MHz. All ADC reference voltages are generated internally.

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TVP5147M1PFP

SLES140A—March 2007

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Texas Instruments TVP5147M1PFP manual Analog Input Clamping, Automatic Gain Control, Analog Video Output, 5 A/D Converters

TVP5147M1PFP specifications

The Texas Instruments TVP5147M1PFP is a versatile video decoder that stands out in the realm of analog video processing. This device is particularly designed for high-quality video applications, making it an excellent choice for a variety of consumer and professional electronics that require reliable video decoding capabilities.

One of the main features of the TVP5147 is its ability to decode multiple video formats, including NTSC, PAL, and SECAM. This flexibility allows the decoder to seamlessly interface with various video sources from different geographic regions, providing a global solution for video applications. The TVP5147 includes advanced synchronization features, ensuring it can effectively handle video signals that may vary in timing and quality.

The device is equipped with a sophisticated 10-bit analog-to-digital converter (ADC), which enhances the precision and clarity of the digital video output. This high-resolution capability allows for improved color accuracy and detail, leading to a more lifelike video representation. Additionally, the TVP5147 utilizes advanced digital processing technologies, including noise reduction and image enhancement features, contributing to outstanding image quality even in less than ideal input conditions.

Another notable characteristic of the TVP5147M1PFP is its support for various output formats, including ITU-R BT.601 and 656, which facilitates easy integration into different systems. The device can also provide various output resolutions, catering to the needs of diverse applications ranging from standard definition to high definition displays.

In terms of connectivity, the TVP5147 offers multiple input options, including composite video, S-video, and component video interfaces. This versatility ensures that it can accommodate a wide range of video sources, from traditional VHS players to modern digital cameras. Furthermore, the integrated video control features allow for easy adjustment of parameters such as brightness, contrast, and saturation.

The power consumption of the TVP5147M1PFP is optimized for low-energy applications while maintaining high performance, making it suitable for battery-powered devices and energy-efficient designs. Overall, the Texas Instruments TVP5147M1PFP is an exceptional video decoder that blends flexibility, high quality, and advanced technology, making it a preferred choice for video processing in numerous consumer and industrial applications. Its combination of features ensures reliable performance and high-quality output, fulfilling the demands of modern multimedia environments.