AD7111LNZ

Overview

The AD7111LNZ is a monolithic logarithmic digital-to-analog converter (DAC) from Analog Devices, packaged in a 16-pin Plastic DIP. It attenuates an analog input signal over a dynamic range of 0 dB to 88.5 dB with a nominal resolution of 0.375 dB. The device utilizes an internal 17-bit R-2R ladder driven by decoded 8-bit data. It operates on a single +5 V supply and features edge-triggered write logic for standard microprocessor interfacing. The component is designed for applications requiring precise, wide-range signal attenuation.

Feature Summary

• Logarithmic Attenuation: Provides 0 dB to 88.5 dB range in 0.375 dB steps using a 17-bit R-2R DAC architecture.
• Microprocessor Interface: Accepts 8-bit parallel data with edge-triggered WR and CS control signals.
• Single Supply Operation: Functions with a +5 V power supply and low current consumption.
• High Resolution: Offers fine step resolution across the entire dynamic range for precision control.

Applications

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

Procurement Notes

Verify the ordering suffix 'N' corresponds to the 16-pin Plastic DIP package as specified in the datasheet. Confirm the grade 'L' indicates the commercial temperature range of 0°C to +70°C. Ensure the specific part number matches the required accuracy and monotonicity specifications for the target application environment.

Selection Notes

Select the AD7111LNZ when a wide dynamic range logarithmic attenuation is required with high resolution. The L-grade variant is suitable for commercial temperature environments (0°C to +70°C). Consider the AD7111A if level-triggered latch operation or pin compatibility with the AD7524 is necessary instead of the edge-triggered logic found in the AD7111.

Part Context

The AD7111LNZ belongs to the LOGDAC family of multiplying D/A converters. It is distinct from the AD7111A due to its edge-triggered write mechanism, whereas the AD7111A offers transparent latch operation. The 'L' designation specifies the commercial temperature grade, differentiating it from industrial (B/C) or extended (T/U) temperature variants available in other packages.

Replacement Considerations

The AD7111A series serves as a functional replacement where transparent latch operation is preferred. For direct pin-compatible upgrades from industry-standard 8-bit multiplying DACs, the AD7111A is explicitly noted as compatible with the AD7524. Verify that the edge-triggered interface of the AD7111LNZ aligns with the existing system timing requirements.