AD7401AYRWZ

ADCs/DACs - Special Purpose Overview

The AD7401AYRWZ is a second-order sigma-delta modulator featuring on-chip digital isolation based on iCoupler technology. It converts analog input signals into a high-speed 1-bit data stream with a maximum clock rate of 20 MHz. The device operates from a 5 V supply (VDD1) and accepts pseudo-differential inputs of ±250 mV, with a full-scale range up to ±320 mV. Serial I/O supports 3 V or 5 V logic (VDD2). Key static performance metrics include 16-bit resolution with no missing codes, typical INL of ±2 LSB, and offset drift of 1 µV/°C. Dynamic specifications at 25°C yield an SNR of 83 dB and SINAD of 82 dB. Power consumption is 93.5 mW at 5.5 V supplies.

ADCs/DACs - Special Purpose Feature Summary

• Integrated digital isolation using iCoupler technology with 5000 Vrms rated dielectric insulation voltage.
• Second-order sigma-delta modulation providing 16-bit resolution without missing codes.
• On-chip voltage reference and continuous sampling eliminating the need for external sample-and-hold circuits.
• Wide operating temperature range from -40°C to +125°C in a 16-lead SOIC package.

ADCs/DACs - Special Purpose Applications

• AC motor controls
• Shunt current monitoring
• Data acquisition systems
• Analog-to-digital and opto-isolator replacements

ADCs/DACs - Special Purpose Procurement Notes

Verify the specific suffix 'YRWZ' against the manufacturer's ordering guide to confirm packaging details such as reel size or tape width. Ensure that the required isolation voltage ratings align with safety standards like UL 1577 or VDE 0884-17 for the target application environment. Confirm power supply requirements for both the isolated side (VDD1) and non-isolated side (VDD2) during procurement planning.

ADCs/DACs - Special Purpose Selection Notes

Select the AD7401A when system design requires galvanic isolation between analog sensing elements and digital processing units. The internal reference simplifies the signal chain by removing external components. Consider the 20 MHz maximum clock rate and subsequent digital filter decimation rates to determine the final data throughput and resolution trade-offs. Ensure the driving source can handle the switched capacitor input currents.

ADCs/DACs - Special Purpose Part Context

The AD7401A belongs to a family of isolated sigma-delta modulators designed for high-performance data acquisition. It serves as a bridge between low-voltage analog sensors and high-voltage digital domains. The internal clock variant is designated as AD7400A. Evaluation boards such as EVAL-AD7401AEDZ are available for performance verification.

ADCs/DACs - Special Purpose Replacement Considerations

Public confirmed substitute part numbers are not provided in the verified documentation. Designers replacing legacy optocouplers should verify that the new solution meets the required creepage and clearance distances specified in DIN EN IEC 60747-17.

ADCs/DACs - Special Purpose FAQ

Does the AD7401A require an external sample-and-hold circuit?

No, the analog input is continuously sampled by the internal second-order modulator, eliminating the need for external sample-and-hold circuitry.

What is the maximum recommended analog input voltage range?

The specified input voltage range is ±200 mV, with a typical range of ±250 mV. The absolute full-scale range extends to ±320 mV.

How is the original information reconstructed from the output?

The 1-bit data stream must be processed by an appropriate digital filter, such as a sinc3 filter, to reconstruct the original multi-bit word.