AD7747ARUZ

ADCs/DACs - Special Purpose Overview

The AD7747ARUZ is a high-resolution, sigma-delta capacitance-to-digital converter (CDC) manufactured by Analog Devices Inc. It features 24-bit resolution with no missing codes and up to 19.5-bit effective resolution. The device interfaces directly with single-ended or differential grounded capacitive sensors, offering an input range of ±8 pF and supporting up to 17 pF common-mode capacitance via an internal CAPDAC. It includes an on-chip temperature sensor with 0.1°C resolution and a voltage input channel. Powered by a single supply from 2.7 V to 5.25 V, it operates within the automotive temperature range of −40°C to +125°C in a 16-lead TSSOP package.

ADCs/DACs - Special Purpose Feature Summary

• Interfaces to single or differential grounded sensors with resolution down to 20 aF
• Includes programmable on-chip digital-to-capacitance converter (CAPDAC) for balancing common-mode capacitance
• Integrated on-chip temperature sensor with 0.1°C resolution and ±2°C accuracy
• Features active AC shielding capability to minimize parasitic capacitance effects

ADCs/DACs - Special Purpose Applications

• Pressure measurement systems
• Position sensing applications
• Proximity sensing devices
• Level sensing instruments
• Flow metering equipment

ADCs/DACs - Special Purpose Procurement Notes

Verify the specific ordering suffix ARUZ corresponds to the 16-lead TSSOP package variant. Confirm that the required operating environment falls within the specified −40°C to +125°C automotive temperature range. Ensure the system design accommodates the 2.7 V to 5.25 V single-supply voltage requirements and I2C-compatible serial interface logic levels.

ADCs/DACs - Special Purpose Selection Notes

Select the AD7747ARUZ when interfacing with grounded capacitive sensors requiring high precision. For floating capacitive sensors, consider the AD7745 or AD7746 instead. Evaluate the need for the integrated temperature sensor and voltage input channel to determine if external components can be eliminated. Verify that the required update rate between 5 Hz and 45 Hz meets the application's dynamic response needs.

ADCs/DACs - Special Purpose Part Context

The AD7747 is part of Analog Devices' specialized capacitance-to-digital converter family designed for direct sensor interface. It utilizes a sigma-delta architecture to achieve high linearity and accuracy without extensive external calibration. The device integrates essential functions such as clock generation and voltage reference, simplifying the overall system design for industrial and automotive sensor applications.

ADCs/DACs - Special Purpose Replacement Considerations

For floating capacitive sensors, the AD7745 (single channel) or AD7746 (dual channel) are recommended alternatives. These devices share similar architectural features but are optimized for different sensor grounding configurations compared to the grounded-sensor-focused AD7747.