Overview
The AD7745ARUZ-REEL7, produced by Analog Devices Inc., is a high-resolution, Σ-Δ capacitance-to-digital converter (CDC). This device is designed to measure capacitance directly connected to its inputs, featuring a 24-bit resolution with no missing codes and up to 21-bit effective resolution. It is particularly suited for applications involving floating capacitive sensors. The AD7745 includes an on-chip voltage reference and an internal clock generator, eliminating the need for external components in capacitive sensor applications. This converter operates on a single supply voltage ranging from 2.7V to 5.25V and has an operating temperature range of -40°C to +125°C.
Key Specifications
| Parameter | Min | Typ | Max | Unit | Test Conditions/Comments |
|---|---|---|---|---|---|
| Conversion Input Range | ±4.096 pF | pF | Factory calibrated | ||
| Integral Nonlinearity (INL) | ±0.01 % of FSR | % | No missing codes | ||
| Resolution | 24 Bit | Bit | No missing codes | ||
| Effective Resolution | Up to 21 Bit | Bit | Conversion time = 62 ms | ||
| Output Noise, rms | 2 aF/√Hz | aF/√Hz | See Table 5 | ||
| Absolute Error | ±4 fF | fF | 25°C, VDD = 5 V, after offset calibration | ||
| Voltage Supply | 2.7 V | 5.25 V | V | Single supply operation | |
| Operating Temperature | -40°C | +125°C | °C | ||
| Package | 16-lead TSSOP | ||||
| Data Interface | 2-wire serial (I2C®-compatible) | ||||
| Temperature Sensor Resolution | 0.1°C | °C | |||
| Temperature Sensor Accuracy | ±2°C | °C |
Key Features
- High resolution (24-bit no missing codes, up to 21-bit effective resolution)
- High linearity (±0.01% of FSR) and high accuracy (±4 fF factory calibrated)
- Single capacitance input channel, configurable as single-ended or differential
- On-chip voltage reference and internal clock generator
- 2-wire serial interface (I2C®-compatible)
- On-chip temperature sensor with 0.1°C resolution and ±2°C accuracy
- Voltage input channel and internal clock oscillator
- Simultaneous 50 Hz and 60 Hz rejection at 16 Hz
- Tolerant of parasitic capacitance to ground up to 60 pF
- Operating temperature range from -40°C to +125°C
- 16-lead TSSOP package
Applications
- Automotive systems
- Industrial systems
- Medical systems
- Pressure measurement
- Position sensing
- Level sensing
- Flowmeters
- Humidity sensing
- Impurity detection
Q & A
- What is the resolution of the AD7745ARUZ-REEL7?
The AD7745ARUZ-REEL7 has a 24-bit resolution with no missing codes and up to 21-bit effective resolution.
- What is the operating temperature range of the AD7745ARUZ-REEL7?
The operating temperature range is from -40°C to +125°C.
- What type of data interface does the AD7745ARUZ-REEL7 use?
The device uses a 2-wire serial interface (I2C®-compatible).
- Does the AD7745ARUZ-REEL7 have an on-chip 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 voltage supply range for the AD7745ARUZ-REEL7?
The voltage supply range is from 2.7V to 5.25V.
- What types of sensors can the AD7745ARUZ-REEL7 be configured for?
The device can be configured for single-ended or differential floating capacitive sensors.
- What is the typical application of the AD7745ARUZ-REEL7 in industrial settings?
Typical applications include pressure measurement, position sensing, level sensing, and humidity sensing.
- Is the AD7745ARUZ-REEL7 RoHS compliant?
Yes, the AD7745ARUZ-REEL7 is RoHS compliant.
- What is the package type of the AD7745ARUZ-REEL7?
The device comes in a 16-lead TSSOP package.
- How does the AD7745ARUZ-REEL7 handle parasitic capacitance?
The device is tolerant of parasitic capacitance to ground up to 60 pF.
