AD7746ARUZ-REEL7

ADCs/DACs - Special Purpose Overview

The AD7746ARUZ-REEL7 is a 2-channel, 24-bit Sigma-Delta capacitance-to-digital converter (CDC) from Analog Devices. It features high resolution down to 4 aF (up to 21 ENOB), ±0.01% linearity, and ±4 fF accuracy. The device operates on a single supply of 2.7 V to 5.25 V with 0.7 mA current consumption. It includes an on-chip temperature sensor (0.1°C resolution, ±2°C accuracy), internal voltage reference, and clock oscillator. Communication is via a 2-wire I²C-compatible serial interface. It tolerates up to 60 pF parasitic capacitance to ground and supports update rates from 10 Hz to 90 Hz.

ADCs/DACs - Special Purpose Feature Summary

• 24-bit Σ-Δ Capacitance-to-Digital Converter with 2 independent channels
• High precision: 4 fF absolute error, ±0.01% linearity, 4 aF resolution
• On-chip Temperature Sensor (0.1°C resolution, ±2°C accuracy)
• I²C-compatible 2-wire serial interface with internal clock and reference
• Tolerant of 60 pF parasitic capacitance to ground; 16-lead TSSOP package

ADCs/DACs - Special Purpose Applications

• Pressure measurement systems
• Position sensing applications
• Level sensing and flowmeters
• Humidity sensing and impurity detection

ADCs/DACs - Special Purpose Procurement Notes

Verify the REEL7 suffix indicates tape-and-reel packaging containing 1000 units per reel. Confirm the ARUZ designation corresponds to the automotive-grade temperature range (-40°C to +125°C) and TSSOP-16 package. Ensure compatibility with I²C bus voltage levels (2.7 V to 5.25 V) during integration.

ADCs/DACs - Special Purpose Selection Notes

Select the AD7746 over the AD7745 when two independent capacitance channels are required. Use this component for floating capacitive sensors; for grounded sensors, consider the AD7747. Verify that the application requires the specific 24-bit resolution and low-power constraints supported by the 2.7 V to 5.25 V supply range.

ADCs/DACs - Special Purpose Part Context

This part belongs to the AD7745/AD7746 family of high-resolution capacitance-to-digital converters. The AD7746 variant specifically provides two capacitance input channels, whereas the AD7745 offers only one. Both share identical architecture, including the Sigma-Delta modulator, digital filter, and integrated peripherals like the temperature sensor and CAPDAC.

ADCs/DACs - Special Purpose Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.