AD7829BRUZ-REEL7

Overview

The AD7829BRUZ-REEL7 is an 8-channel, 8-bit 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. The device supports single-ended inputs with spans of 2 V (at 3 V supply) or 2.5 V (at 5 V supply), adjustable via the VMID pin. It operates on dual supplies ranging from 2.7 V to 3.3 V and 4.5 V to 5.5 V, consuming up to 36 mW in normal operation. The component is housed in a 28-lead TSSOP package and includes a flexible parallel interface with automatic power-down capabilities.

Feature Summary

• Integrates an on-chip 2.5 V reference and track-and-hold amplifier for simplified system design.
• Features a half-flash ADC architecture enabling high-speed 420 ns conversions.
• Supports automatic power-down at the end of conversion to minimize energy consumption.
• Allows analog input span adjustment via the VMID pin to accommodate various signal ranges.

Applications

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

Procurement Notes

Verify the specific ordering suffix REEL7 corresponds to tape-and-reel packaging when sourcing components. Confirm that the B version meets the required industrial temperature range specifications. Ensure compatibility with the intended microprocessor interface logic levels before finalizing procurement orders.

Selection Notes

Select this model for applications requiring eight simultaneous single-ended channels. Verify that the 8-bit resolution and 2 MSPS throughput align with system bandwidth requirements. Consider the half-flash architecture's noise performance relative to SAR alternatives if dynamic linearity is critical for the specific application environment.

Part Context

This component belongs to the AD7822/AD7825/AD7829 family of sampling ADCs. While sharing identical core conversion specifications, the AD7829 is distinguished by its provision of eight analog input channels, whereas the AD7822 offers one channel and the AD7825 provides four channels within the same architectural framework.

Replacement Considerations

The AD7829BRUZ-1 is documented as a parameter-equivalent alternative within the same product family.

FAQ

How does the AD7829 achieve automatic power-down?

The device checks the logic level on the CONVST pin at the end of a conversion. If the signal is low, the ADC automatically enters power-down mode.

What is the function of the VMID pin?

The VMID pin allows the user to offset the analog input span, centering it anywhere between AGND and VDD to accommodate system offsets or specific voltage ranges.

Can the AD7829 operate without an external reference?

Yes, the device includes an on-chip 2.5 V reference with a 2% tolerance, though an external reference can also be connected to the VREF IN/OUT pin.