AD7854SQ

Overview

The AD7854SQ is a high-speed, low-power 12-bit analog-to-digital converter (ADC) from Analog Devices Inc. It operates on a single 3 V to 5.5 V supply and supports throughput rates up to 200 kSPS. The device features a pseudo-differential track-and-hold amplifier with an acquisition time of 500 ns. It includes self-calibration and system calibration capabilities to maintain accuracy over temperature variations. Power management options include automatic power-down after conversion, achieving typical dissipation of 1 mW at 10 kSPS. The component utilizes a flexible parallel interface and is housed in a 28-lead Cerdip package.

Feature Summary

• Integrated self-calibration and system calibration mechanisms for long-term accuracy
• Flexible power management with multiple low-power modes including automatic shutdown
• Pseudo-differential analog input architecture supporting unipolar and bipolar ranges
• Versatile parallel I/O port compatible with standard microprocessor buses

Applications

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

Procurement Notes

Verify the specific suffix SQ indicates the extended industrial temperature range of -55°C to +125°C compared to commercial variants. Confirm package type Q-28 corresponds to the 28-lead Cerdip configuration. Ensure compatibility with existing board layouts regarding pin assignments and thermal requirements for the specified operating environment.

Selection Notes

Select the AD7854SQ when operation beyond the standard commercial temperature range is required. Compare power consumption profiles against the AD7854L variant if lower static current is prioritized over maximum throughput speed. Verify that the parallel interface timing constraints align with the host processor's bus specifications for reliable data transfer.

Part Context

This component belongs to the AD7854 family of 12-bit sampling ADCs manufactured by Analog Devices. The family includes variants optimized for different performance trade-offs, such as the AD7854L for reduced power consumption. The SQ designation specifically denotes the version qualified for extended temperature applications, distinguishing it from standard commercial grade parts within the same functional series.

Replacement Considerations

Direct substitutes include other AD7854 variants with different temperature ratings or packages, such as AD7854AR or AD7854ARS. Cross-vendor replacements require verification of pin compatibility, resolution, and interface protocols.