AD7829BRUZ-1REEL7

Overview

The AD7829BRUZ-1REEL7 is an 8-bit, 8-channel analog-to-digital converter (ADC) from Analog Devices Inc., operating at a maximum throughput of 2 MSPS. It features a half-flash architecture with a conversion time of 420 ns and includes an on-chip 2.5 V reference. The device supports single-ended inputs with spans of 2 V (3 V supply) or 2.5 V (5 V supply), adjustable via the VMID pin. It utilizes a flexible parallel interface with automatic power-down capabilities and operates within a temperature range of -40°C to +85°C in a 28-lead TSSOP package.

Feature Summary

• Integrates an on-chip track-and-hold amplifier and a 2.5 V reference for simplified system design.
• Features an automatic power-down mode triggered by the CONVST pin state at the end of conversion.
• Provides channel selection without requiring write operations to the device.
• Includes an input offset adjustment capability via the VMID pin to accommodate various signal ranges.

Applications

• Data acquisition systems
• DSP front ends
• Disk drives
• Mobile communication systems
• Subsampling applications

Procurement Notes

Verify the specific ordering suffix REEL7 corresponds to tape-and-reel packaging when sourcing components. Confirm that the BRUZ designation indicates the industrial temperature grade (-40°C to +85°C) and TSSOP-28 package. Ensure compatibility with the required supply voltage range of 3 V ± 10% or 5 V ± 10% for the target application environment.

Selection Notes

Select this component for applications requiring high-speed multiplexed sampling with moderate resolution. The half-flash architecture offers fast conversion times suitable for real-time processing. Consider the available input span adjustments and the integrated reference when evaluating power consumption and board space constraints compared to external reference solutions.

Part Context

This part belongs to the AD7829-1 series, which is a variant of the standard AD7829 featuring input offset adjust capabilities. It shares the same core ADC architecture and performance specifications but provides additional flexibility for single-supply op amp requirements and system offset compensation through the VMID pin configuration.

Replacement Considerations

The AD7829BRUZ is a parameter-equivalent alternative within the same family. Verify if the non-adjustable offset version meets the design requirements, as it lacks the VMID pin functionality present in the AD7829-1 variant.

FAQ

How does the AD7829-1 handle power consumption during idle periods?

The device implements an automatic power-down mode at the end of each conversion. If the CONVST pin is logic low when the End of Conversion (EOC) signal goes high, the ADC powers down, reducing current consumption to a maximum of 5 μA.

What is the function of the VMID pin?

The VMID pin allows the user to center the analog input span anywhere between AGND and VDD. This feature helps reduce the requirements for single-supply op amps and accommodates system offsets or bipolar signals.

Can the AD7829-1 operate in a stand-alone manner?

Yes, the EOC pulse allows the ADC to be used in a stand-alone manner. The parallel interface is designed to allow easy interfacing to microprocessors and DSPs using only address decoding logic.