AD7854ARSZ

Overview

The AD7854ARSZ is a 12-bit, single-channel Analog-to-Digital Converter (ADC) manufactured by Analog Devices Inc. It operates from a single 3 V to 5.5 V supply and supports throughput rates up to 200 kSPS with a master clock frequency of 4 MHz. The device features a pseudo-differential analog input range of 0 V to VREF or ±VREF/2. It utilizes a flexible parallel interface with 12-bit data output and includes on-chip self-calibration and system calibration capabilities. Power consumption is typically 15 mW in normal operation at 3 V, with automatic power-down modes reducing dissipation to 1.3 mW at 10 kSPS.

Feature Summary

• Integrated self-calibration and system calibration mechanisms for maintaining accuracy over temperature and time.
• Flexible parallel I/O port supporting both 12-bit and 8-bit data bus configurations via High Byte Enable control.
• Multiple power management options including automatic power-down after conversion to optimize energy efficiency.
• Pseudo-differential sampling scheme with track-and-hold acquisition time of 500 ns.

Applications

• Battery-powered systems such as personal digital assistants and mobile communications devices.
• Medical instruments requiring precise signal acquisition.
• Pen computers and portable instrumentation.
• Instrumentation and control systems.
• High-speed modems.

Procurement Notes

Verify the specific suffix ARSZ corresponds to the SSOP-28 package and commercial temperature range (-40°C to +85°C). Confirm that the ordering part number matches the required linearity grade (A version with ±1 LSB INL) and power specifications. Ensure compatibility with the 28-lead shrink small outline package dimensions during PCB layout.

Selection Notes

Select the AD7854ARSZ when high speed (200 kSPS) is prioritized over ultra-low power consumption compared to the AD7854L variant. Ensure the application requires a parallel interface rather than serial communication. Verify that the 12-bit resolution and pseudo-differential input architecture meet the system's dynamic performance requirements, specifically SNR and THD specifications at the target sampling rate.

Part Context

The AD7854 is part of the AD7854/AD7854L family of high-speed, low-power 12-bit ADCs. The AD7854 variant is optimized for maximum throughput speed, whereas the AD7854L is optimized for lower power consumption with a reduced 100 kSPS rate. Both share similar architectural features but differ in performance trade-offs regarding speed and power dissipation.

Replacement Considerations

The AD7854LARSZ is a compatible alternative within the same family if lower power consumption is required, though it operates at a reduced 100 kSPS throughput rate. Other members of the AD7854 family include the AD7854AR (SOIC package) and AD7854AQ (Cerdip package), which offer different physical footprints while maintaining identical electrical characteristics.