AD7854BR

Overview

The AD7854BR is a 12-bit, high-speed analog-to-digital converter (ADC) from Analog Devices Inc., optimized for speed within the AD7854 family. It operates on 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 input architecture with an acquisition time of 0.5 µs. It includes internal self-calibration and system calibration capabilities to maintain accuracy over temperature variations. Power consumption is typically 15 mW in normal operation at 3 V, dropping to 25 µW in automatic power-down mode after conversion.

Feature Summary

• Flexible parallel interface supporting both 12-bit and 8-bit data bus configurations via High Byte Enable control.
• Integrated self-calibration and system calibration functions to correct offset and gain errors over time and temperature.
• Multiple power management options including automatic power-down after conversion to minimize energy usage in battery-powered applications.

Applications

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

Procurement Notes

Verify the specific suffix 'BR' indicates the SOIC-28 package variant when sourcing. Confirm that the B version meets the required integral nonlinearity specification of ±0.5 LSB compared to the A version's ±1 LSB rating. Ensure compatibility with the 3 V to 5.5 V supply range required for this component.

Selection Notes

Select the AD7854BR over the AD7854L variant if higher throughput speeds up to 200 kSPS are required, as the L version is limited to 100 kSPS. Consider the B version's tighter linearity specification of ±0.5 LSB if higher DC accuracy is needed compared to the standard A version. Ensure the design accommodates the 28-lead SOIC package footprint and thermal requirements.

Part Context

The AD7854BR belongs to the AD7854/AD7854L series of 12-bit sampling ADCs manufactured by Analog Devices. This series distinguishes between speed-optimized (AD7854) and low-power (AD7854L) variants. The BR suffix specifically denotes the commercial temperature range (-40°C to +85°C) and the SOIC-28 surface-mount package type.

Replacement Considerations

The AD7854ARZ serves as a direct pin-compatible replacement offering identical electrical performance but housed in a 28-lead SOIC package. For lower power requirements, the AD7854LARZ provides similar functionality with reduced throughput and power consumption. Verify package dimensions and pinout compatibility before substitution.