原标题：TI THS7319三路集成滤波器的视频放大方案

　　TI 公司的THS7319是集成了滤波器的非常低功耗的单电源(2.6V-5V)三路视频放大器.THS7319集成了三路增强分辨率(ED)的滤波器,具有三阶Butterworth特性.可用作DAC重建滤波器或ADC抗混淆滤波器.THS7319在3.3V时的总静态电流仅为3.4mA,非常适合以电池为能源的应用,如PMP,数码相机,手机视频输出缓冲和USB/手提低功耗视频缓冲.本文介绍了THS7319主要特性,方框图, 标准测试电路以及多种应用电路,包括单电源DC耦合输入/DC耦合输出视频线路驱动器,DC耦合编码器/DAC和DC耦合线路驱动器的THS7319系统, 驱动AC耦合视频线路的DC输入系统.此外还介绍了THS7319 EVM评估板电路图和评估板材料清单.

　　Fabricated using the revolutionary, complementary Silicon-Germanium (SiGe) BiCom3X process, the THS7319 is a very low-power, 2.6-V to 5-V single-supply, three-channel, integrated filter video buffer. This device is ideal for battery-powered applications where size and power are critical parameters. Total quiescent current is only 3.4 mA at 3.3 V and can be reduced to 0.15 µA while disabled.

　　The THS7319 incorporates three enhanced definition (ED) filter channels with third-order Butterworth characteristics. These filters are useful as digital-to-analog converter (DAC) reconstruction filters or as analog-to-digital converter (ADC) anti-aliasing filters supporting 480p/576p YPBPR and RGB video. The THS7319 is also ideal for oversampled systems that produce standard-definition (SD) signals including CVBS, S-Video, 480i/576i YPBPR, YUV, and RGB.

　　The THS7319 is designed for dc-coupled inputs. To mitigate any DAC/encoder termination interaction, the input impedance is a very high 2.4 M

. The 150-mV output level shift allows for a full sync dynamic range at the output with a 0-V input that prevents sync crushing. The rail-to-rail output stage supports both ac and dc line driving.

　　The THS7319 is offered in a RoHS-compliant ultra-small 9-ball MicrostarCSP package that measures 1.5-mm × 1.5-mm × 0.35-mm.

　　THS7319主要特性:

　　Very Low Total Quiescent Current: 3.4 mA at 3.3 V

　　0.15-µA Total Disabled Supply Current

　　Third-Order Butterworth Low-Pass Filters:

　　-1 dB at 17 MHz

　　-3 dB at 20 MHz

　　21-dB Attenuation at 43 MHz

　　Supports 480p/576p YPBPR or RGB Video

　　Supports CVBS, S-Video, 480i/576i YPBPR, or YUV in Oversampled Systems

　　DC-Coupled Input with 150-mV Output Shift

　　Built-in 6-dB Gain (2 V/V)

　　+2.6-V to +5-V Single-Supply Operation

　　Rail-to-Rail Output Allows AC or DC Output Coupling

　　Low Differential Gain/Phase of 0.05%/0.03°

　　Ultra-Small, 1.5-mm × 1.5-mm × 0.35-mm, MicrostarCSP™ 9-Ball Package

　　THS7319应用:

　　Personal Media Players

　　Digital Cameras

　　Cellular Phone Video Output Buffering

　　USB/Portable Low-Power Video Buffering

　　图1.THS7319功能方框图

　　图2.THS7319标准测试电路

　　图3.THS7319单电源DC耦合输入/DC耦合输出视频线路驱动器

　　图4.典型的THS7319系统:DC耦合编码器/DAC和DC耦合线路驱动器

　　图5.驱动AC耦合视频线路的典型THS7319DC输入系统

　　图6.THS7319 EVM评估板电路图

　　THS7319 EVM评估板材料清单(BOM):