AD5421BREZ-REEL7

Digital To Analog Converters Overview

The AD5421BREZ-REEL7 is a 16-bit, serial input, loop-powered digital-to-analog converter (DAC) designed for industrial process control applications. It features a fully integrated architecture with an internal current setting resistor and on-chip voltage references (1.22 V and 2.5 V). The device supports a flexible SPI-compatible 3-wire interface operating up to 30 MHz and includes a regulated voltage output for powering transmitter circuits. Key electrical specifications include a maximum total unadjusted error (TUE) of 0.05%, integral nonlinearity (INL) of 0.0035% FSR, and a quiescent current of 300 μA maximum. It operates within a loop voltage range of 5.5 V to 52 V and is specified over an extended temperature range of −40°C to +105°C in a TSSOP-28 package.

Digital To Analog Converters Feature Summary

• 16-bit resolution with guaranteed monotonicity and pin-selectable NAMUR-compliant ranges (4 mA to 20 mA, 3.8 mA to 21 mA, 3.2 mA to 24 mA)
• Integrated power management including a regulated voltage output (1.8 V to 12 V) and on-chip 2.5 V/1.22 V references
• High-speed 3-wire SPI-compatible serial interface with automatic fault register readback and slew rate control
• On-chip fault alerts via FAULT pin or alarm currents (3.2 mA downscale, 22.8 mA/24 mA upscale)

Digital To Analog Converters Applications

• Industrial process control systems
• 4 mA to 20 mA loop-powered transmitters
• Smart transmitters with HART network connectivity

Digital To Analog Converters Procurement Notes

Verify the specific grade (B or C) associated with the REEL7 suffix against the manufacturer's ordering guide, as accuracy parameters such as Total Unadjusted Error (TUE) vary by grade. Confirm that the reel packaging matches the required quantity for production runs. Ensure compatibility with the target microcontroller's SPI voltage levels, as the digital interface thresholds are referenced to the IODVDD supply.

Digital To Analog Converters Selection Notes

Select this component when a high-precision, low-power solution for loop-powered instrumentation is required. The internal 24 kΩ resistor simplifies design but offers lower accuracy than external resistor configurations; use external RSET if tighter error budgets are needed. Verify that the application requires the specific NAMUR alarm currents and that the 30 MHz serial clock speed aligns with the host processor capabilities.

Digital To Analog Converters Part Context

The AD5421 belongs to Analog Devices' family of precision loop-powered DACs. The BREZ-REEL7 designation indicates a B-grade device packaged in a TSSOP-28 housing and supplied in a reel format. It serves as a direct replacement for older discrete solutions in 4-20 mA loops, integrating functions previously handled by separate regulators, references, and amplifiers into a single compact IC.

Digital To Analog Converters Replacement Considerations

Direct pin-compatible replacements within the same series include the AD5421CREZ-RL7 (C-grade) for cost-sensitive applications with relaxed accuracy requirements. For higher precision needs, the AD5421AREZ variant offers tighter error specifications. Ensure that any substitute maintains the same TSSOP-28 footprint and thermal characteristics.