基于LTC2259-16的16位模-数转换方案

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LTC2259-16是 16位模-数转换器,适用于对高频宽动态范围的信号进行数字化.它的SNR为73.1db,SFDR为88db,单电源1.8V工作,功率89mW,具有CMOS, DDR CMOS 或DDR LVDS输出,可选择的输入范围从1VP-P 到 2VP-P,主要用于通信,蜂窝基站,SDR,手提医疗图像设备,多路数据采集和非破坏性测试.本文介绍了LTCR2259-16主要特性, 功能方框图, 采用变压器模拟输入(5MHz-70MHz)电路图,以及70MHz到170MHz, 170MHz到270MHz, 大于270MHz和采用高速差分放大器的前端输入电路图, LTC2259-16典型应用电路图.The LTCR2259-16 is a sampling 16-bit A/D converter designed for digitizing high frequency, wide dynamic range signals. It is perfect for demanding communications applications with AC performance that includes 73.1db SNR and 88db spurious free dynamic range (SFDR). Ultralow jitter of 0.17psRMS allows undersampling of IF frequencies with excellent noise performance. DC specs include ±4LSb INL (typical) and ±0.5LSb DNL (typical).The digital outputs can be either full-rate CMOS, doubledata rate CMOS, or double-data rate LVDS. A separate output power supply allows the CMOS output swing to range from 1.2V to 1.8V.The ENC+ and ENC– inputs may be driven differentially or single ended with a sine wave, PECL, LVDS, TTL or CMOS inputs. An optional clock duty cycle stabilizer allows high performance at full speed for a wide range of clock duty cycles.LTCR2259-16主要特性:73.1db SNR88db SFDRLow Power: 89mWSingle 1.8V SupplyCMOS, DDR CMOS or DDR LVDS OutputsSelectable Input Ranges: 1VP-P to 2VP-P800MHz Full-Power bandwidth S/HOptional Data Output RandomizerOptional Clock Duty Cycle StabilizerShutdown and Nap ModesSerial SPI Port for Configuration40-Pin (6mm x 6mm) QFN PackageLTCR2259-16应用:CommunicationsCellular base StationsSoftware Defi ned RadiosPortable Medical ImagingMulti-Channel Data AcquisitionNondestructive Testing

图1.LTCR2259-16功能方框图

图2.LTCR2259-16采用变压器模拟输入(5MHz-70MHz)电路图

图3.LTCR2259-16 70MHz到170MHz前端输入电路图
                          
                       
                          
                               

图3.LTCR2259-16 170MHz到270MHz前端输入电路图

图4.LTCR2259-16 大于270MHz前端输入电路图

图5.LTCR2259-16 采用高速差分放大器的前端输入电路图

图6.LTC2259-16 应用电路