GENERAL DESCRIPTION

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-tocapacitance converter (CAPDAC).

FEATURES

Capacitance-to-digital converter

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

APPLICATIONS

Automotive, industrial, and medical systems for

Pressure measurement

Position sensing

Level sensing

Flowmeters

Humidity sensing

Impurity detection

AD7745ARUZ-REEL属于集成电路（IC） > ADC/DAC - 特殊用途。亚德诺半导体技术有限公司制造生产的AD7745ARUZ-REELADC/DAC - 特殊用途该产品族中的产品可用于模拟和数字表示的信息转换，适用于特定用例，或集成了通用数据转换器中不常见的其他功能。例如针对超声或汽车雷达应用集成了低噪声放大器和可变增益级的器件、注重音频和视频的产品、在段码式显示器上集成显示测量值功能的器件、集成输入输出电气隔离的器件等。