AD7731:CMOS、低噪声、24位Σ-Δ型ADC,快速通道建立时间

AD7731: CMOS、低噪声、24位Σ-Δ型ADC,快速通道建立时间

AD7731是一款适合过程控制应用的完整模拟前端,它拥有专有可编程增益前端,能够直接接收来自传感器的各种输入信号范围,包括低电平信号。该器件的Σ-Δ架构由模拟调制器和低通可编程数字滤波器组成,滤波器截止、输出速率和建立时间可通过编程进行调整。

AD7731具有3个缓冲差分可编程增益模拟输入（也可以配置为5个伪差分输入）和1个差分基准电压输入,采用+5 V单电源供电,接受七种单极性模拟输入范围：0至+20 mV、+40 mV、+80 mV、+160 mV、+320 mV、+640 mV和+1.28 V,以及七种双极性输入：±20 mV、±40 mV、±80 mV、±160 mV、±320 mV、±640 mV和±1.28 V。输出速率为800 Hz时,该器件可实现直接16位峰－峰值分辨率。AD7731的通道间切换建立时间为1 ms,且峰－峰值分辨率可维持在13位。

该器件上的串行接口可配置用于三线式操作,并且与微控制器和数字信号处理器兼容。AD7731包含自校准和系统校准选项,失调漂移小于5 nV/°C,增益漂移小于2 ppm/°C。该器件提供24引脚塑料DIP、24引脚SOIC和24引脚TSSOP三种封装。

The AD7731 is a complete analog front-end for process control applications. The device has a proprietary programmable gain front end that allows it to accept a range of input signal ranges, including low level signals, directly from a transducer. The sigma-delta architecture of the part consists of an analog modulator and a low pass programmable digital filter, allowing adjustment of filter cutoff, output rate and settling time.

The part features three buffered differential programmable gain analog inputs (which can be configured as five pseudo-differential inputs), as well as a differential reference input. The part operates from a single +5 V supply and accepts seven unipolar analog input ranges: 0 to +20 mV, +40 mV, +80 mV, +160 mV, +320 mV, +640 mV and +1.28 V, and seven bipolar ranges: ±20 mV, ±40 mV, ±80 mV, ±160 mV, ±320 mV, ±640 mV and ±1.28 V. The peak-to-peak resolution achievable directly from the part is 16 bits at an 800 Hz output rate. The part can switch between channels with 1 ms settling time and maintain a performance level of 13 bits of peak-to-peak resolution.

The serial interface on the part can be configured for three-wire operation and is compatible with microcontrollers and digital signal processors. The AD7731 contains self-calibration and system calibration options and features an offset drift of less than 5 nV/°C and a gain drift of less than 2 ppm/°C.

AD7731 特点

24位Σ-Δ型ADC
16位峰－峰值分辨率（800 Hz输出速率）
最高6.4 kHz的可编程输出速率
可编程增益前端
非线性度：±0.0015%
缓冲差分输入
可编程滤波器截止
FASTStep™通道序列化模式
单电源工作
24-Bit Sigma-Delta ADC
16 Bits p-p Resolution at 800 Hz Output Rate
Programmable Output Rates up to 6.4 kHz
Programmable Gain Front End
±0.0015% Nonlinearity
Buffered Differential Inputs
Programmable Filter Cutoffs
FASTStep™ Mode for Channel Sequencing
Single Supply Operation

AD7731 技术指标

Resolution (Bits): 24bit
# Chan: 3
Sample Rate: 5MSPS
Interface: Ser,SPI
Analog Input Type: Diff-Bip,Diff-Uni
Ain Range: (2Vref/PGA Gain) p-p,(Vref/PGA Gain) p-p
ADC Architecture: Sigma-Delta
Pkg Type: DIP,SOIC,SOP

AD7731 功能框图

AD7731 芯片订购指南

产品型号	产品状态	封装	引脚	温度范围
AD7731BN	量产	24 ld PDIP	24	工业
AD7731BNZ	量产	24 ld PDIP	24	工业
AD7731BR	量产	24 ld SOIC - Wide	24	工业
AD7731BR-REEL	量产	24 ld SOIC - Wide	24	工业
AD7731BR-REEL7	量产	24 ld SOIC - Wide	24	工业
AD7731BRU	量产	24 ld TSSOP	24	工业
AD7731BRU-REEL	量产	24 ld TSSOP	24	工业
AD7731BRU-REEL7	量产	24 ld TSSOP	24	工业
AD7731BRUZ	量产	24 ld TSSOP	24	工业
AD7731BRUZ-REEL	量产	24 ld TSSOP	24	工业
AD7731BRUZ-REEL7	量产	24 ld TSSOP	24	工业
AD7731BRZ	量产	24 ld SOIC - Wide	24	商业
AD7731BRZ-REEL	量产	24 ld SOIC - Wide	24	商业
AD7731BRZ-REEL7	量产	24 ld SOIC - Wide	24	商业
EVAL-AD7731EBZ	量产	评估板	-	待定