AD7854ARS

Overview

The AD7854ARS is a 12-bit analog-to-digital converter (ADC) from Analog Devices, housed in a 28-lead SSOP package. It operates on a single 3 V to 5.5 V supply and supports throughput rates up to 200 kSPS with a master clock of 4 MHz. The device features a pseudo-differential input range of 0 to VREF or bipolar ±VREF/2. Key electrical parameters include a typical Signal-to-Noise + Distortion Ratio (SNDR) of 70 dB, Total Harmonic Distortion (THD) of -78 dB max, and Integral Nonlinearity of ±1 LSB. Power consumption is typically 15 mW at 3 V in normal operation, dropping to 25 µW in automatic power-down mode.

Feature Summary

• Integrated self-calibration and system calibration capabilities to maintain accuracy over temperature and time variations.
• Flexible parallel interface supporting both 12-bit and 8-bit data bus configurations via High Byte Enable control.
• Multiple power management modes including automatic power-down after conversion for optimized energy efficiency.
• Pseudo-differential analog input structure allowing unipolar or bipolar signal acquisition relative to the reference voltage.

Applications

• Battery-powered systems such as personal digital assistants and mobile communications devices.
• Medical instruments requiring precise low-power signal acquisition.
• Instrumentation and control systems utilizing pen computers or high-speed modems.

Procurement Notes

Verify the specific suffix 'ARS' corresponds to the 28-lead SSOP package and commercial temperature range (-40°C to +85°C). Confirm that the ordering part number matches the required linearity grade (A version: ±1 LSB INL) and power specifications. Ensure compatibility with existing PCB footprints for SSOP-28 components during procurement planning.

Selection Notes

Select the AD7854ARS when a 12-bit resolution and 200 kSPS speed are required within a 3 V to 5 V single-supply environment. Choose this component over the AD7854L variant if higher throughput is prioritized over ultra-low power consumption. Ensure the application can accommodate the 28-lead SSOP footprint and provides adequate thermal dissipation for the specified power levels.

Part Context

The AD7854ARS belongs to the AD7854 family of high-speed, low-power sampling ADCs manufactured by Analog Devices. This series includes variants optimized for different performance trade-offs, such as the AD7854L for lower power applications. The ARS designation specifically identifies the SSOP package option within the standard commercial temperature range lineup.

Replacement Considerations

Direct pin-compatible replacements within the same family include the AD7854AR (SOIC package) and AD7854AQ (Cerdip package), provided the package form factor change is acceptable. For lower power requirements, the AD7854LARSZ offers similar functionality with reduced throughput and power consumption.