AD7745ARUZ: 24位、单通道电容数字转换器
AD7745/AD7746均为高分辨率、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21位有效分辨率）、高线性度（±0.01%）和高精度（±4 fF工厂校准）等固有特性。AD7745/AD7746的电容输入范围是±4 pF（可变）,同时可接受最大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。AD7745拥有一个电容输入通道,AD7746则拥有两个通道。每个通道均可配置为单端输入或差分输入方式。AD7745/AD7746针对浮动式电容传感器而设计。若需一块极板接地的电容传感器,推荐使用AD7747。
这些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。两款器件都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。AD7745/AD7746均有一个双线式I²C兼容串行接口,二者均可采用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 AD7745/AD7746 are 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 21-bit effective resolution), high linearity (±0.01%), and high accuracy (±4 fF factory calibrated). The AD7745/AD7746 capacitance input range is ±4 pF (changing), while 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 AD7745 has one capacitance input channel, while the AD7746 has two channels. Each channel can be configured as single-ended or differential. The AD7745/AD7746 are designed for floating capacitive sensors. For capacitive sensors with one plate connected to ground, theAD7747 is recommended.
The parts have 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 parts have a standard voltage input, which together with the differential reference input allows easy interface to an external temperature sensor, such as an RTD, thermistor, or diode.
The AD7745/AD7746 have a 2-wire, I²C-compatible serial interface. Both parts can operate with a single power supply from 2.7 V to 5.25 V. They are specified over the automotive temperature range of –40°C to +125°C and are housed in a 16-lead TSSOP package.
产品应用领域 Applications
汽车电子、工业和医疗系统,用于：
- 压力测量
- 位置传感器
- 液位传感器
- 流量计
- 湿度传感器
- 杂质检测
产品应用领域 Applications
Automotive, Industrial and Medical Systems for:
- Pressure Measurement
- Position Sensors
- Level Sensors
- Flowmeters
- Humidity Sensors
- Impurity Detection
AD7745ARUZ 特点
电容数字转换器
- 采用单芯片解决方案的新标准
- 可与单一或差分浮动式传感器接口
- 分辨率：最低4 aF（即最高21 ENOB）
- 精度：4 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：±4 pF
- 耐受对地寄生电容：最大60 pF
- 更新速率：10 Hz～90 Hz
- 16 Hz时,50 Hz、60 Hz同时抑制
- 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
- New standard in single chip solutions
- Interfaces to single or differential floating sensors
- Resolution down to 4 aF (that is, up to 21 ENOB)
- Accuracy: 4 fF
- Linearity: 0.01%
- Common-mode (not changing) capacitance up to 17 pF
- Full-scale (changing) capacitance range: ±4 pF
- Tolerant of parasitic capacitance to ground up to 60 pF
- Update rate: 10 Hz to 90 Hz
- Simultaneous 50 Hz and 60 Hz rejection at 16 Hz >
- Temperature sensor on-chip
▪ Resolution: 0.1°C, accuracy: ±2°C - Voltage input channel
- Internal clock oscillator
- 2-wire serial interface (I²C®-compatible)
- Power
▪ 2.7 V to 5.25 V single-supply operation
▪ 0.7 mA current consumption - Operating temperature: –40°C to +125°C
- 16-lead TSSOP package
AD7745ARUZ 功能框图
| 产品型号 | 产品状态 | 封装 | 引脚 | 温度范围 |
|---|---|---|---|---|
| AD7745ARUZ | Prodn | 16 ld TSSOP | 16 | 工业 |
| AD7745ARUZ-REEL | Prodn | 16 ld TSSOP | 16 | 工业 |
| AD7745ARUZ-REEL7 | Prodn | 16 ld TSSOP | 16 | 工业 |
AD7745ARUZ 应用技术支持与电子电路设计开发资源下载
- AD7745 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
