AD7825BRU

Overview

The AD7825BRU is an 8-bit, 4-channel analog-to-digital converter with a maximum throughput of 2 MSPS. It utilizes a half-flash architecture and features a 420 ns conversion time. The device operates on a single supply voltage ranging from 3 V ± 10% to 5 V ± 10%. Key electrical parameters include a signal-to-noise ratio of 48 dB minimum, integral nonlinearity of ±0.75 LSB, and differential nonlinearity of ±0.75 LSB. Power consumption is typically 24 mW during normal operation and drops to 5 μA in power-down mode.

Feature Summary

• Half-flash ADC architecture providing fast 420 ns conversion times for real-time DSP processing.
• On-chip track-and-hold amplifier capable of handling full-scale input signals up to 10 MHz.
• Integrated 2.5 V reference voltage with 2% tolerance to simplify external circuit design.
• VMID pin allows adjustment of the analog input span offset to accommodate system offsets.

Applications

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

Procurement Notes

Verify the specific package variant (e.g., SOIC or TSSOP) against the required board layout, as the base part number may correspond to multiple physical packages. Confirm that the ordering suffix matches the intended reel or tube packaging configuration. Ensure the voltage rating aligns with the target system's supply rails before finalizing procurement.

Selection Notes

Select this component when four single-ended channels are required at high speeds. Compare channel count and resolution against alternatives like the AD7822 (1 channel) or AD7829 (8 channels). Consider the parallel interface requirements and ensure the microprocessor can handle the EOC pulse timing. Evaluate power constraints if automatic power-down functionality is critical for the application.

Part Context

This device belongs to the AD7822/AD7825/AD7829 family of high-speed sampling ADCs. It shares the same core half-flash architecture and performance characteristics as its siblings, differing primarily in the number of analog input channels. The family is designed for microprocessor-compatible interfaces and offers flexible power management options.

Replacement Considerations

Direct functional substitutes within the same family include the AD7822 for single-channel applications and the AD7829 for eight-channel requirements. Verify pin compatibility and interface logic levels when substituting. Check datasheet revisions to ensure timing characteristics remain consistent across different manufacturing batches.