AD7856AN

Overview

The AD7856AN is an 8-channel, 14-bit successive approximation register (SAR) analog-to-digital converter manufactured by Analog Devices. It operates from a single +5 V supply and supports a throughput rate of 285 kSPS with a typical power dissipation of 60 mW in normal mode. The device features a flexible serial interface compatible with SPI, QSPI, and 8051 protocols. It includes internal self-calibration and system calibration capabilities to maintain accuracy over temperature variations. The input range extends from 0 V to the reference voltage, supporting both single-ended and pseudo-differential configurations.

Feature Summary

• Integrated self-calibration and system calibration mechanisms ensure long-term accuracy without external trimming.
• Flexible serial communication interface supports multiple standard protocols including SPI and QSPI for easy microcontroller integration.
• Low power architecture includes automatic power-down after conversion to minimize energy consumption in battery-operated applications.

Applications

• Battery-powered portable systems such as personal digital assistants and mobile communications devices
• Medical instrumentation requiring high-resolution signal acquisition
• Instrumentation and control systems needing multi-channel data acquisition

Procurement Notes

Verify the specific grade version required for your application temperature range before ordering. The 'AN' suffix denotes the plastic DIP package variant. Confirm that the supplier provides genuine Analog Devices components to ensure performance specifications are met. Check for end-of-life status or obsolescence notices as availability may be limited.

Selection Notes

Select the AD7856AN when a through-hole 24-lead DIP package is required for prototyping or legacy board designs. Ensure the system clock frequency does not exceed 6 MHz for the A-grade version. Consider the AD7856ARZ if a surface-mount SOIC package is preferred for automated assembly processes.

Part Context

The AD7856 belongs to the AD7856 family of high-speed, low-power ADCs from Analog Devices. It shares core functional specifications with variants like the AD7856AR and AD7856ARS, differing primarily in packaging options. This component is designed for applications requiring moderate speed and high resolution with minimal external support circuitry.

Replacement Considerations

Direct pin-compatible replacements include the AD7856AR (SOIC package) and AD7856ARS (SSOP package). Verify that any substitute maintains the same 14-bit resolution and 285 kSPS throughput rate. Ensure the replacement part supports the required serial interface modes and power supply voltage range.