AD7111ABRZ

Overview

The AD7111ABRZ is a monolithic logarithmic multiplying digital-to-analog converter (DAC) from Analog Devices, part of the LOGDAC family. It features a 17-bit R-2R ladder architecture that translates an 8-bit parallel input into precise attenuation steps. The device operates on a single +5 V supply and provides a dynamic range of 0 dB to 88.5 dB with a nominal resolution of 0.375 dB. Designed for industrial applications, it functions within a temperature range of -40°C to +85°C. The component utilizes a standard microprocessor interface with edge-triggered write control and includes on-chip data latches for signal holding.

Feature Summary

• Logarithmic Attenuation: Provides 0 dB to 88.5 dB attenuation in 0.375 dB steps using a 17-bit internal R-2R ladder.
• Parallel Interface: Accepts 8-bit binary data via D0–D7 pins with dedicated Chip Select (CS) and Write (WR) control lines.
• Single Supply Operation: Functions with a +5 V power supply, drawing a maximum digital current of 1 mA at typical conditions.
• Industrial Temperature Range: Rated for operation between -40°C and +85°C with specified accuracy and monotonicity.

Applications

• Audio Attenuators
• Sonar Systems
• Function Generators
• Digitally Controlled AGC Systems

Procurement Notes

Verify the specific grade suffix 'AB' confirms the industrial temperature range (-40°C to +85°C) and the 'RZ' suffix indicates the RoHS-compliant 16-SOIC package. Confirm availability status as distribution channels may list this component as discontinued or obsolete. Ensure ESD precautions are observed during handling due to the CMOS construction.

Selection Notes

Select the AD7111ABRZ when high-resolution logarithmic attenuation is required over a wide dynamic range. The 8-bit input simplifies microprocessor interfacing compared to linear DACs requiring more bits for equivalent resolution. Ensure the output amplifier selection supports the required bandwidth and has low input bias current to minimize offset errors caused by the varying source impedance of the DAC.

Part Context

The AD7111ABRZ belongs to the AD7111/AD7111A LOGDAC series. The 'A' designation indicates the AD7111A variant, which features level-triggered WR inputs allowing transparent latch operation, unlike the edge-triggered AD7111. This model is pin-compatible with the industry-standard AD7524, facilitating upgrades in existing designs while providing superior dynamic range and step resolution.

Replacement Considerations

The AD7111A is pin-compatible with the AD7524. Designers upgrading from AD7524 can utilize the AD7111ABRZ directly without schematic changes, benefiting from the wider dynamic range and finer resolution.