AD7304BRU

Overview

The AD7304BRU is a quad, 8-bit digital-to-analog converter (DAC) from Analog Devices. It operates on single +3 V to +5 V or ±5 V supplies, consuming less than 9 mW at 3 V. The device features four independent channels with rail-to-rail buffered outputs and an external reference input range spanning both supply rails. It utilizes a 3-wire SPI-compatible serial interface for data loading. Key electrical parameters include 1 LSB maximum integral and differential nonlinearity, a 2.6 MHz reference multiplying bandwidth, and a typical settling time of 1 µs to ±0.1% full scale.

Feature Summary

• Quad 8-bit DAC architecture with internal precision buffers providing true rail-to-rail output swing.
• SPI-compatible 3-wire serial interface (SDI, CLK, CS) with double-buffered input registers.
• Rail-to-rail reference input allows positive or negative full-scale output voltages relative to supply rails.
• Internal power-on reset initializes outputs to zero scale; hardware shutdown reduces current to 40 µA.

Applications

• Automotive output span voltage control
• Instrumentation and digitally controlled calibration systems
• Pin-compatible replacement for AD7226 when operating below 5.5 V

Procurement Notes

Verify the package type matches the specific suffix requirements. The standard BRU designation indicates a TSSOP-16 package. Confirm that the serial interface requirement aligns with the AD7304 model rather than the parallel AD7305. Ensure the design supports the necessary external reference voltage configuration within the specified supply ranges.

Selection Notes

Select the AD7304BRU when a serial interface is preferred over the parallel AD7305. Verify that the application requires four independent channels with individual reference inputs (VREFA through VREFD). Ensure the system can accommodate the TSSOP-16 footprint and that the 8-bit resolution meets the required accuracy specifications for the target application.

Part Context

The AD7304 belongs to the AD7304/AD7305 family of quad 8-bit DACs. It differs from the AD7305 primarily in its serial interface and having four separate reference inputs instead of one common reference. Both devices share identical internal DAC architectures and rail-to-rail output capabilities, allowing for flexible interface selection based on system bus constraints.

Replacement Considerations

The datasheet identifies the AD7304 as a pin-compatible replacement for the AD7226 when the supply voltage is less than 5.5 V. Designers should verify that the lower supply voltage operation and serial interface compatibility meet the existing system requirements before substituting.