AD7856KRZ

Overview

The AD7856KRZ is a high-speed, low-power 14-bit analog-to-digital converter manufactured by Analog Devices Inc. It operates from a single 5 V supply and supports an 8-channel input configuration, accommodating either eight single-ended or four pseudo-differential signals. The device delivers a throughput rate of 285 kSPS with a typical power consumption of 60 mW in normal operation. It features self-calibration and system calibration options to maintain accuracy over time and temperature variations. The component utilizes a flexible serial interface compatible with SPI, QSPI, 8051, and microprocessor modes. Designed for commercial applications, it functions within a temperature range of 0°C to +105°C and is housed in a 24-lead SOIC package.

Feature Summary

• Supports eight single-ended or four pseudo-differential analog inputs via a multiplexed track-and-hold circuit.
• Includes on-chip self-calibration and system calibration logic to correct offset and gain errors automatically.
• Features multiple power-down modes controlled by software bits and the SLEEP pin to minimize energy usage.
• Provides a versatile serial interface compatible with standard communication protocols including SPI and QSPI.

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 K grade designation ensures compliance with the commercial temperature range of 0°C to +105°C. Confirm that the 24-lead SOIC package matches the target PCB footprint. Ensure the design accounts for the 5 V single supply requirement and appropriate reference voltage connections. Check for end-of-life status if long-term availability is critical for the production timeline.

Selection Notes

Select this component when a 14-bit resolution and 285 kSPS sampling rate are required for multi-channel data acquisition. The K grade variant is suitable for commercial environments operating between 0°C and +105°C. Consider the integrated calibration features if system-level accuracy without external trimming is necessary. Verify that the available serial interface modes align with the host controller's capabilities.

Part Context

The AD7856KRZ belongs to the AD7856 family of 5 V single-supply ADCs. It shares core specifications with the A grade version but differs in the guaranteed operating temperature range and maximum clock frequency limits. The KR suffix indicates the SOIC package option within the broader product line that also includes DIP and SSOP variants.

Replacement Considerations

The AD7856ARZ serves as a direct functional substitute within the same family, offering identical electrical performance but rated for an extended industrial temperature range of -40°C to +105°C. Designers should verify thermal requirements before swapping between the K and A grades.