原标题：TI ADS8331 16位500kSPS模数转换方案

　　TI 公司的ADS8331 是低功耗16位500kSPS模数转换器(ADC),包括16位基于电容的SAR ADC和取样保持电路,同时具有单极4:1复接器的输入.ADS8331工作电压2.7V-5.5V,主要用在通信,传感器接口,医疗设备,磁力计,工业过程控制,数据采集系统和自动测试设备(ATE).本文介绍ADS8331主要特性, 方框图, 单极和双极输入驱动配置, 采用菊花链模式的多个转换器连接图以及典型应用电路.

　　The ADS8331 is a low-power, 16-bit, 500k samples-per-second (SPS) analog-to-digital converter (ADC) with a unipolar, 4-to-1 multiplexer (mux) input. The device includes a 16-bit capacitor-based successive approximation register (SAR) ADC with inherent sample and hold.

　　The ADS8332 is based on the same core and includes a unipolar 8-to-1 input mux. Both devices offer a high-speed, wide-voltage serial interface and are capable of daisy-chain operation when multiple converters are used.

　　These converters are available in 24-pin, 4x4 QFN and 24-pin TSSOPTSSOP (PW) package available Q1, 2010. packages and are fully specified for operation over the industrial –40℃ to +85℃ temperature range.

　　ADS8331主要特性:

　　Low-Power, Flexible Supply Range:

　　2.7V to 5.5V Analog Supply

　　8.7mW (250kSPS in Auto-Nap Mode, VA = 2.7V, VBD = 1.65V)

　　14.2mW (500kSPS, VA = 2.7V, VBD = 1.65V)

　　Up to 500kSPS Sampling Rate

　　Excellent DC Performance:

　　±1.2 LSB Typ, ±2 LSB Max INL at 2.7V

　　±0.6 LSB Typ, –1.0/1.5 LSB Max DNL at 2.7V

　　16-Bit NMC Over Temperature

　　Excellent AC Performance at 5V, fIN = 1kHz:

　　91.5dB SNR, 101dB SFDR, –100dB THD

　　Flexible Analog Input Arrangement:

　　On-Chip 4-/8-Channel Mux with Breakout

　　Auto/Manual Channel Select and Trigger

　　Other Hardware Features:

　　On-Chip Conversion Clock (CCLK)

　　Software/Hardware Reset

　　Programmable Status/Polarity EOC/INT

　　Daisy-Chain Mode

　　Global CONVST (Independent of CS)

　　ADS8331应用:

　　• Communications

　　• Transducer Interfaces

　　• Medical Instruments

　　• Magnetometers

　　• Industrial Process Control

　　• Data Acquisition Systems

　　• Automatic Test Equipment

　　图1.ADS8331方框图

　　图2.单极输入驱动配置

　　图3.双极输入驱动配置

　　图4.采用菊花链模式的多个转换器连接图

　　图5.ADS8331/32典型应用电路