AD7854LARZ

Overview

The AD7854LARZ is a 12-bit successive approximation analog-to-digital converter (ADC) manufactured by Analog Devices Inc. It operates from a single 3 V to 5.5 V supply and supports a maximum throughput rate of 100 kSPS. The device features a pseudo-differential input architecture with an acquisition time of 500 ns. Power consumption is typically 5.5 mW in normal operation at 3 V, dropping to 650 µW at 10 kSPS. It includes self-calibration and system calibration capabilities to maintain accuracy over temperature variations. The component utilizes a flexible parallel interface and is housed in a 28-lead SSOP package.

Feature Summary

• Integrated self-calibration and system calibration mechanisms for long-term accuracy
• Flexible power management with automatic power-down modes after conversion
• Pseudo-differential analog input structure supporting unipolar and bipolar ranges
• Versatile parallel I/O port compatible with 8-bit and 16-bit data buses

Applications

• Battery-powered systems such as personal digital assistants and mobile communications
• Medical instruments requiring low power consumption
• Pen computers and portable instrumentation
• Instrumentation and control systems
• High-speed modems

Procurement Notes

Verify the specific suffix 'R' indicates the SOIC package variant when sourcing. Confirm the 'L' designation corresponds to the low-power 100 kSPS version rather than the standard 200 kSPS model. Ensure the operating voltage range matches the 3 V to 5.5 V specification. Check for moisture sensitivity level requirements during storage and handling. Validate that the 28-lead SSOP footprint aligns with the PCB design constraints.

Selection Notes

Select the AD7854LARZ when a balance between moderate speed and low power is required. The L-series variant is optimized for lower power dissipation compared to the standard AD7854. Consider the 12-bit resolution and pseudo-differential inputs for applications needing noise immunity. Verify compatibility with the available parallel bus width and clock frequencies. Evaluate the need for internal calibration features to reduce external component count.

Part Context

The AD7854LARZ belongs to the AD7854 family of high-speed, low-power sampling ADCs. This series includes variants optimized for different performance trade-offs, such as the standard AD7854 for higher speeds. The 'L' suffix denotes the low-power version, while 'AR' specifies the SOIC package type. The family shares common architectural features like SAR conversion and on-chip registers.

Replacement Considerations

Public confirmed substitute part numbers are not provided in the verified documentation.