AD7829BRU-REEL

Overview

The AD7829BRU-REEL is an 8-bit, 8-channel analog-to-digital converter (ADC) from Analog Devices Inc., operating at a maximum throughput of 2 MSPS. It utilizes a half-flash architecture with a conversion time of 420 ns and features an on-chip track-and-hold amplifier capable of handling input frequencies up to 10 MHz. The device supports dual supply voltages of 3 V ± 10% and 5 V ± 10%, with corresponding input spans of 2 V p-p and 2.5 V p-p. Key specifications include an integral nonlinearity (INL) and differential nonlinearity (DNL) of ±0.75 LSB max, a signal-to-noise ratio of 48 dB min, and power consumption of 24 mW typical in normal operation. It employs a flexible parallel interface with automatic power-down capabilities.

Feature Summary

• Integrates an on-chip 2.5 V reference and a high-speed track-and-hold amplifier for efficient data acquisition.
• Features a half-flash conversion architecture that combines fast conversion speeds with low power consumption.
• Includes an input offset adjust pin (VMID) to center the analog input span within the supply range.
• Supports automatic power-down at the end of conversion via the CONVST pin logic state sampling.

Applications

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

Procurement Notes

Verify the specific ordering suffix against the manufacturer's current documentation to confirm packaging type and reel specifications. Ensure compatibility with existing system voltage levels and interface requirements before integration. Cross-reference the component revision history for any updates to electrical characteristics or pin configurations.

Selection Notes

Select this component for applications requiring multiple single-ended inputs with moderate resolution and high speed. Consider the available channel count and the need for an internal reference. Evaluate the power consumption requirements against the available supply voltage options to ensure optimal performance within the specified temperature range.

Part Context

This part belongs to the AD7822/AD7825/AD7829 family of high-speed, microprocessor-compatible ADCs. While the AD7822 offers one channel and the AD7825 offers four, the AD7829 provides eight channels. All variants share similar architectural features, including the half-flash conversion technique and parallel interface design.

Replacement Considerations

Public confirmed substitute part numbers are not provided in the verified source material. Consult official distributor databases for parameter-equivalent alternatives if direct replacement is required.

FAQ

How does the AD7829 handle power-down?

The AD7829 implements automatic power-down at the end of a conversion. The logic level on the CONVST pin is sampled after the EOC signal goes high; if it is logic low, the ADC powers down.

What is the function of the VMID pin?

The VMID pin allows the user to offset the input span. It centers the analog input range anywhere between AGND and VDD, reducing the requirements for single-supply op amps and accounting for system offsets.

What is the full power bandwidth of the track-and-hold amplifier?

The track-and-hold amplifier has a full power bandwidth sufficient to convert full-scale input signals up to a frequency of 10 MHz, making it suitable for subsampling applications.