Overview
The AD7747ARUZ-REEL, produced by Analog Devices Inc., is a high-resolution, Σ-Δ capacitance-to-digital converter (CDC) designed for precise capacitance measurements. This device is integrated with a temperature sensor and various features that make it suitable for a wide range of applications. The AD7747 connects directly to the capacitance to be measured and offers high resolution, linearity, and accuracy, making it an ideal choice for automotive, industrial, and medical systems.
Key Specifications
| Specification | Value |
|---|---|
| Resolution | 24-bit (up to 19.5-bit effective resolution) |
| Capacitance Range | ±8 pF (changing), up to 17 pF common-mode capacitance |
| Update Rate | 5 Hz to 45 Hz |
| Temperature Sensor Resolution | 0.1°C |
| Temperature Sensor Accuracy | ±2°C |
| Power Supply | 2.7 V to 5.25 V single-supply operation |
| Current Consumption | 0.7 mA |
| Operating Temperature | −40°C to +125°C |
| Package | 16-lead TSSOP |
| Interface | 2-wire serial interface (I2C compatible) |
Key Features
- High-resolution, Σ-Δ capacitance-to-digital conversion with up to 19.5-bit effective resolution.
- High linearity (±0.01%) and high accuracy (±10 fF factory calibrated).
- On-chip temperature sensor with 0.1°C resolution and ±2°C accuracy.
- On-chip voltage reference and clock generator, eliminating the need for external components.
- Active shield for shielding sensor connections.
- Simultaneous 50 Hz and 60 Hz rejection at 8.1 Hz update rate.
- Programmable on-chip digital-to-capacitance converter (CAPDAC) for balancing common-mode capacitance.
- Standard voltage input channel for interfacing with external temperature sensors like RTDs, thermistors, or diodes.
Applications
- Automotive systems: Pressure measurement, position sensing, proximity sensing, level sensing, flow metering, and impurity detection.
- Industrial systems: Similar applications as in automotive, including monitoring and control systems.
- Medical systems: Precise measurements in medical devices, such as those requiring capacitance and temperature sensing.
Q & A
- What is the resolution of the AD7747? The AD7747 has a 24-bit resolution with up to 19.5-bit effective resolution.
- What is the capacitance range of the AD7747? The capacitance range is ±8 pF (changing) with up to 17 pF common-mode capacitance.
- What is the update rate of the AD7747? The update rate ranges from 5 Hz to 45 Hz.
- Does the AD7747 have a built-in temperature sensor? Yes, it has an on-chip temperature sensor with a resolution of 0.1°C and accuracy of ±2°C.
- What is the power supply range for the AD7747? The device operates with a single power supply of 2.7 V to 5.25 V.
- What is the current consumption of the AD7747? The current consumption is 0.7 mA.
- What is the operating temperature range of the AD7747? The operating temperature range is −40°C to +125°C.
- What type of interface does the AD7747 use? The AD7747 uses a 2-wire serial interface (I2C compatible).
- What package type is the AD7747 available in? The AD7747 is available in a 16-lead TSSOP package.
- Can the AD7747 be used with floating capacitive sensors? No, for floating capacitive sensors, the AD7745 or AD7746 are recommended instead.
