LTC2311特性及演示板2425A主要特性

　　Linear公司的LTC2311-16是低噪音高速16位SAR5MspsADC，差分输入和宽输入共模范围，单电源3.3V或5V工作，差分输入范围8VP-P，fIN = 2.2MHz时的SNR为81dB，THD为-90dB，16位时±3LSB INL，不会丢失码，主要用在高速数据采集系统，通信，遥控数据采集，图像，光网络，汽车电子和对相马达控制。本文介绍了LTC2311特性，框图，应用电路以及演示板2425A主要特性，连接图，电路图，材料清单和PCB元件布局图。

　　The LTCR2311-16 is a low noise， high speed 16-bitsuccessive approximation register （SAR） ADC withdifferential inputs and wide input common mode range.

　　Operating from a single 3.3V or 5V supply， the LTC2311-16 has an 8VP-P differential input range， making it idealfor applications which require a wide dynamic range withhigh common mode rejection. The LTC2311-16 achieves±3LSB INL typical， no missing codes at 16 bits and 81dBSNR typical.

　　The LTC2311-16 has an onboard low drift （20ppm/℃ max）2.048V or 4.096V temperature-compensated reference andprovides an external 1.25V buffered reference input. TheLTC2311-16 also has a high speed SPI-compatible serialinterface that supports CMOS or LVDS. The fast 5Mspsthroughput with one-cycle latency makes the LTC2311-16ideally suited for a wide variety of high speed applications.

　　The LTC2311-16 dissipates only 50mW with a 5V supplyand offers nap and sleep modes to reduce the powerconsumption to 5μW for further power savings duringinactive periods.

　　LTC2311特性：

　　5Msps Throughput Rate

　　±3LSB INL （Typ）， ±8LSB INL Guaranteed

　　Guaranteed 16-Bit， No Missing Codes

　　8VP-P Differential Inputs with Wide Input CommonMode Range

　　81dB SNR （Typ） at fIN = 2.2MHz

　　–90dB THD （Typ） at fIN = 2.2MHz

　　Guaranteed Operation –40℃ to 125℃

　　Single 3.3V or 5V Supply

　　Low Drift （20ppm/℃ Max） 2.048V or 4.096V InternalReference with 1.25V External Reference Input

　　1.8V to 2.5V I/O Voltages

　　CMOS or LVDS SPI-Compatible Serial I/O

　　Power Dissipation 50mW at VDD = 5V （Typ）

　　Small 16-Lead （4mm × 5mm） MSOP Package

　　LTC2311应用：

　　High Speed Data Acquisition Systems

　　Communications

　　Remote Data Acquisition

　　Imaging

　　Optical Networking

　　Automotive

　　Multiphase Motor Control

图1.LTC2311框图:CMOS I/O模式

图2.LTC2311框图:LVDS I/O模式

　　图3.LTC2311全差分应用电路

　　演示板2425A

　　Demonstration circuit 2425A features the LTC®2311 family.With up to 5Msps， these differential， single channel， 16-bit，serial， high speed successive approximation register（SAR） ADCs are available in a 16-lead MSOP package.

　　The LTC2311 family has an internal 20ppm/°C maximumdrift reference and an SPI-compatible serial interface thatsupports CMOS and LVDS logic. Note the demo board isconfigured for CMOS operation by default; see the noteunder JP3 for LVDS operation. The following text refersto the LTC2311， but applies to all members of the family，the only difference being the sample rate and/or thenumber of bits. The DC2425A demonstrates the DC andAC performance of the LTC2311 in conjunction with theDC890 PScope™ data collection board. Alternatively， byconnecting the DC2425A into a customer application， theperformance of the LTC2311 can be evaluated directly inthat circuit.

图4.演示板2425A连接示意图

图5.演示板2425A电路图(1)

图6.演示板2425A电路图(2)

演示板2425A材料清单(BOM):

图7.演示板2425A PCB元件布局