AD7747:  内置温度传感器的24位电容数字转换器

AD7747 功能框图AD7747是一款高分辨率、Σ-Δ电容数字转换器(CDC),可直接与电容传感器的电容连接进行测量。该芯片还具有高分辨率(24位无失码、最高19.5位有效分辨率)、高线性度(±0.01%)和高精度(±10 fF工厂校准)等固有特性。AD7747的电容输入范围是±8 pF(可变),而且可接受最大17 pF共模电容(不可变),后者可以通过一个可编程片内数字电容转换器(CAPDAC)来平衡。AD7747针对一块极板接地的单端或差分输入电容传感器设计。对于浮动式(不接地)电容传感器,推荐使用AD7745或AD7746。该器件内置一个片内温度传感器,其分辨率为0.1°C,精度为±2°C;还集成片内基准电压源和片内时钟发生器,因此在电容传感器应用中无需任何额外外部元件。此款器件配有一个标准电压输入,当与差分基准电压输入结合使用时,可方便地与一个外部温度传感器(如RTD、热敏电阻或二极管等)接口。AD7747具有一个双线式I²C兼容串行接口,可采用2.7 V至5.25 V单电源供电,额定温度范围为-40°C至+125°C汽车电子温度范围,采用16引脚TSSOP封装。

The AD7747 is a high-resolution, Σ-Δ capacitance-to-digital converter (CDC). The capacitance to be measured is connected directly to the device inputs. The architecture features inherent high resolution (24-bit no missing codes, up to 19.5-bit effective resolution), high linearity (±0.01%), and high accuracy (±10 fF factory calibrated). The AD7747 capacitance input range is ±8 pF (changing), and it can accept up to 17 pF common-mode capacitance (not changing), which can be balanced by a programmable on-chip digital-to-capacitance converter (CAPDAC).The AD7747 is designed for single-ended or differential capacitive sensors with one plate connected to ground. For floating (not grounded) capacitive sensors, the AD7745 or AD7746 are recommended.The part has an on-chip temperature sensor with a resolution of 0.1°C and accuracy of ±2°C. The on-chip voltage reference and the on-chip clock generator eliminate the need for any external components in capacitive sensor applications. The part has a standard voltage input that, together with the differential reference input, allows easy interface to an external temperature sensor, such as an RTD, thermistor, or diode.The AD7747 has a 2-wire, I²C-compatible serial interface. The part can operate with a single power supply of 2.7 V to 5.25 V. It is specified over the automotive temperature range of −40°C to +125°C and is housed in a 16-lead TSSOP package.

AD7747 特点
  • 采用单芯片解决方案的新标准
  • 可与单一或差分接地式传感器接口
  • 分辨率:最低20 aF(即最高19.5位 ENOB)
  • 精度:10 fF
  • 线性度:0.01%
  • 共模(不可变)电容最大可达17 pF
  • 满量程(可变)电容范围:±8 pF
  • 更新速率:5 Hz~45 Hz
  • 8.1 Hz更新速率时,50 Hz、60 Hz同时抑制
  • 有源屏蔽保护传感器连接
  • 片内温度传感器:分辨率:0.1°C,精度:±2°C
  • 电压输入通道
  • 内部时钟振荡器
  • 双线式串行接口(I²C®兼容)
  • 电源:2.7 V至5.25 V单电源工作
    功耗:0.7 mA
  • 工作温度范围:-40°C~+125°C
  • 16引脚TSSOP封装
AD7747 技术指标
  • Resolution (Bits): 24bit
  • # Chan: 1
  • Sample Rate: n/a
  • Interface: I²C/Ser 2-Wire,Ser
  • Analog Input Type: Diff-Uni,SE-Uni
  • Ain Range: ± 8 pF (Delta C) ,(2Vref) p-p
  • ADC Architecture: Sigma-Delta
  • Pkg Type: SOP
AD7747 应用领域
  • 压力测量
  • 位置传感
  • 近程传感
  • 液位传感
  • 流量计
  • 杂质检测
AD7747 产品选型
产品型号 产品状态 封装 引脚 温度范围
AD7747ARUZ Prodn 16 ld TSSOP 16 工业
AD7747ARUZ-REEL Prodn 16 ld TSSOP 16 工业
AD7747ARUZ-REEL7 Prodn 16 ld TSSOP 16 工业
EVAL-AD7747EBZ Prodn EVALUATION BOARDS - 待定
AD7747 应用技术支持与电子电路设计开发资源下载
  1. AD7747 数据手册DataSheet下载 .pdf
  2. Analog Devices, Inc.ADI 美国模拟器件公司产品订购手册 .pdf
  3. ADC模数转换器选型指南 .pdf