AD7711ANZ: 内置匹配RTD激励电流的CMOS、24位Σ-Δ型信号调理ADC
AD7711是一款适合低频测量应用的完整模拟前端,可直接接受来自传感器的低电平信号,并产生串行数字输出。它采用Σ-Δ转换技术,可实现最高24位无失码性能。输入信号加在一个以模拟调制器为基础的专有可编程增益前端。调制器输出由片内数字滤波器处理。此数字滤波器的第一个陷波可通过片内控制寄存器进行编程,以便对滤波器截止和建立时间进行调整。
该器件具有一个差分模拟输入、一个单端模拟输入和一个差分基准电压输入。一般而言,其中一个输入通道将用作主通道,而另一个通道将用作辅助输入,用来定期检测第二电压输入。如果模拟输入上的输入信号高于-30 mV,则该器件可采用单电源供电（将VSS引脚与AGND相连）。将VSS引脚接负电压时,该器件可转换低至-VREF的输入信号。该器件提供两个电流源,可用来在三线式和四线式RTD配置中提供激励。因此,AD7711能处理单通道或双通道系统所有的信号调节和转换。
AD7711非常适合基于微控制器的智能系统应用。利用双向串行端口,可在软件中进行增益设置、信号极性选择、输入通道选择和RTD电流控制配置。AD7711含有自测量校准、系统校准和后台校准选项,同时允许用户读取和写入片内校准寄存器。
CMOS构造可确保低功耗,软件可编程省电模式则将待机功耗降至仅7 mW（典型值）。该器件提供两种封装：24引脚、0.3英寸宽、塑料密封双列直插式封装（DIP）和24引脚小形集成封装（SOIC）。
The AD7711 is a complete analog front end for low frequency measurement applications. The device accepts low level signals directly from a transducer and outputs a serial digital word. It employs a sigma-delta conversion technique to realize up to 24 bits of no missing codes performance. The input signal is applied to a proprietary programmable gain front end based around an analog modulator. The modulator output is processed by an on-chip digital filter. The first notch of this digital filter can be programmed via the on-chip control register allowing adjustment of the filter cutoff and settling time.
The part features one differential analog input and one single ended analog input as well as a differential reference input. Normally, one of the input channels will be used as the main channel with the second channel used as an auxiliary input to periodically measure a second voltage. It can be operated from a single supply (by tying the VSS pin to AGND) provided that the input signals on the analog inputs are more positive than -30 mV. By taking the VSS pin negative, the part can convert signals down to -VREF on its inputs. The part provides two current sources that can be used to provide excitation in three-wire and four-wire RTD configurations. The AD7711 thus performs all signal conditioning and conversion for a single or dual channel system.
The AD7711 is ideal for use in smart, microcontroller based systems. Gain settings, signal polarity, input channel selection and RTD current control can be configured in software using the bidirectional serial port. The AD7711 contains self-measurement calibration, system calibration and background calibration options and also allows the user to read and write the on-chip calibration registers.
CMOS construction ensures low power dissipation, and a software programmable power-down mode reduces the standby power consumption to only 7 mW typical. The part is available in a 24-pin, 0.3 inch wide, plastic and hermetic dual-in-line package (DIP) as well as a 24-lead small outline (SOIC) package.
AD7711ANZ 特点
- 电荷平衡ADC
- 24位无失码
- ±0.0015%非线性度 - 双通道可编程增益前端
- 增益范围：1至128
- 1个差分输入
- 1个单端输入 - 内置可编程滤波截止的低通滤波器
- 读/写校准系数
- RTD激励电流源
- 双向微控制器串行接口
- 内部、外部基准电压选择
- 单电源或双电源供电
- 低功耗（典型值25 mW）,
带省电模式（典型值7 mW） - Charge-Balancing ADC
- 24 Bits, No Missing Codes
- ±0.0015% Nonlinearity - 2-Channel Programmable Gain Front End
- Gains from 1 to 128
- 1 Differential Input
- 1 Single-Ended Input - Low-Pass Filter with Programmable Filter Cutoffs
- Ability to Read/Write Calibration Coefficients
- RTD Excitation Current Sources
- Bidirectional Microcontroller Serial Interface
- Internal/External Reference Option
- Single- or Dual-Supply Operation
- Low Power (25 mW typ) with Power-Down Mode (7 mW typ)
AD7711ANZ 功能框图
| 产品型号 | 产品状态 | 封装 | 引脚 | 温度范围 |
|---|---|---|---|---|
| AD7711AAR | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7711AARZ | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7711AN | 量产 | 24 ld PDIP | 24 | 工业 |
| AD7711ANZ | 量产 | 24 ld PDIP | 24 | 工业 |
| AD7711AQ | 量产 | CERDIP GLASS SEAL | 24 | 工业 |
| AD7711AR | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7711AR-REEL | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7711AR-REEL7 | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7711ARZ | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7711ARZ-REEL | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7711ARZ-REEL7 | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7711ASQ | 量产 | CERDIP GLASS SEAL | 24 | 军用 |
AD7711ANZ 应用技术支持与电子电路设计开发资源下载
- AD7711 数据手册DataSheet下载 . pdf
- Analog Devices, Inc.ADI 美国模拟器件公司产品订购手册 .pdf
- ADC模数转换器选型指南 . pdf
