AD7854LARSZ

Overview

The AD7854LARSZ is a 12-bit, single-channel Analog-to-Digital Converter (ADC) manufactured by Analog Devices Inc. It utilizes a Successive Approximation Register (SAR) architecture and operates from a single 3 V to 5.5 V supply. The device supports a maximum throughput rate of 100 kSPS with a typical power dissipation of 5.5 mW at 3 V. It features a pseudo-differential analog input range of 0 V to VREF (unipolar) or ±VREF/2 (bipolar). Data is transferred via a flexible parallel interface, supporting both 12-bit and 8-bit modes. The component includes internal self-calibration and system calibration capabilities to maintain accuracy over temperature variations.

Feature Summary

• Low-power SAR ADC optimized for battery-operated applications
• Integrated track-and-hold amplifier with pseudo-differential inputs
• On-chip self-calibration and system calibration registers
• Flexible parallel data interface with automatic power-down

Applications

• Battery-powered medical instruments
• Personal digital assistants and mobile communications
• Pen computers
• Instrumentation and control systems
• High-speed modems

Procurement Notes

Verify the specific suffix 'RS' indicates the 28-lead SSOP package variant. Confirm the 'L' designation corresponds to the low-power 100 kSPS performance tier rather than the standard 200 kSPS version. Ensure the operating voltage range matches the 3 V to 5.5 V specification required for this model.

Selection Notes

Select the AD7854LARSZ when lower power consumption is prioritized over maximum sampling speed compared to the standard AD7854. This model is suitable for applications requiring 100 kSPS throughput with reduced energy usage. Verify that the parallel interface requirements align with the target system bus width and timing constraints.

Part Context

This component belongs to the AD7854 family of high-speed, low-power 12-bit ADCs. The AD7854L variant is specifically engineered for low-power efficiency, offering reduced current draw compared to the standard AD7854 while maintaining 12-bit resolution. It shares the same pinout and register structure but differs in clock frequency limits and power specifications.

Replacement Considerations

The AD7854AR is the higher-speed counterpart within the same family. Substitution requires verifying if the 200 kSPS capability is necessary and if the increased power dissipation is acceptable for the thermal design.