TI THS7365六路视频和滤波方案

TI 公司的THS7365是集成了3-SD和3-HD六阶滤波器的六路视频放大器,增益为6dB. THS7365采用互补的锗硅(SiGe) BiCom3X工艺制造,是低功耗单电源(2.7V-5V)六路集成视频缓冲放大器,有三个标清(SDTV)和三个高清(HDTV)滤波器通路,所有滤波器具有旁路六阶Butterworth滤波器特性,可用作DAC重建滤波器或ADC抗混淆滤波器.主要用于STB输出视频缓冲, PVR/DVDR/BluRay输出缓冲和低功耗视频缓冲.本文介绍了THS7365的主要特性,方框图以及多种应用电路,包括单电源DC输入/DC输出耦合视频线路驱动器, 编码器DC耦合输入/DC耦合的DAC线路驱动的六路系数框图, DC耦合线路驱动和每路双输出的六路系统, 驱动AC耦合视频线路的AC输入系统. 此外还介绍了THS7365 EVM评估板电路图和评估板材料清单(BOM).

6-Channel Video Amplifier with 3-SD and 3-HD Sixth-Order Filters and 6-dB Gain

Fabricated using the revolutionary, complementary Silicon-Germanium (SiGe) BiCom3X process, the THS7365 is a low-power, single-supply, 2.7-V to 5-V, six-channel integrated video buffer. It incorporates three standard-definition (SDTV) and three high-definition (HDTV) filter channels. All filters feature bypassable sixth-order Butterworth filter characteristics that are useful as digital-to-analog converter (DAC) reconstruction filters or as analog-to-digital converter (ADC) anti-aliasing filters.

The THS7365 has flexible input coupling capabilities that can be configured for either ac- or dc-coupled inputs. The 300-mV output level shift allows for a full sync dynamic range at the output with 0-V input. The ac-coupled modes include a transparent sync-tip clamp for composite video (CVBS), Y, and RGB signals with sync. AC-coupled biasing for C/P_B/P_R channels can easily be achieved by adding an external resistor to V_S+.

The THS7365 is an ideal choice for all video buffer applications. Its rail-to-rail output stage with 6-dB gain allows for both ac and dc line driving. The ability to drive two lines per channel, or 75- loads, allows for maximum flexibility as a video line driver. The 20.7-mA total quiescent current at 3.3 V and 0.1 µA (disabled mode) makes it an excellent choice for power-sensitive video applications.

The THS7365 is available in a TSSOP-20 package that is lead-free and green (RoHS-compliant).

THS7365主要特性:

Three SDTV Video Amplifiers for CVBS, S-Video, Y/P_B/P_R, 480i/576i, YUV, or RGB

Three HDTV Video Amplifiers for Y/P_B/P_R, 720p/1080i/1080p30, or GBR (RGB)

Bypassable Sixth-Order Low-Pass Filters:

SD Channels: -3 dB at 9.5-MHz

HD Channels: -3 dB at 36-MHz

Versatile Input Biasing:

DC-Coupled with 300-mV Output Shift

AC-Coupled with Sync-Tip Clamp

AC-Coupling with Biasing

Built-in 6-dB Gain (2 V/V)

+2.7-V to +5-V Single-Supply Operation

Rail-to-Rail Output:

Output Swings Within 100 mV from the Rails: Allows AC or DC Output Coupling

Supports Driving Two Video Lines/Channel

Low Total Quiescent Current: 20.7 mA at 3.3 V

Disabled Supply Current Function: 0.1 µA

Low Differential Gain/Phase: 0.2%/0.3°

RoHS-Compliant Package: TSSOP-20

THS7365应用:

Set Top Box Output Video Buffering

PVR/DVDR/BluRay™ Output Buffering

Low-Power Video Buffering



图1.THS7365功能方框图

图2.THS7365单电源DC输入/DC输出耦合视频线路驱动器

图3.THS7365从编码器DC耦合输入/DC耦合的DAC线路驱动的六路系数框图

图4.典型的六路系统:DC耦合线路驱动和每路双输出

图5.驱动AC耦合视频线路的典型AC输入系统

图6.THS7365 EVM评估板电路图

THS7365 EVM评估板材料清单(BOM):