AD7821KPZ

Overview

The AD7821KPZ is an 8-bit analog-to-digital converter utilizing a half-flash architecture and LC2MOS process. It features a maximum conversion time of 660 ns and supports sampling rates up to 1 MHz with a built-in track-and-hold function. The device operates on a single +5 V supply for unipolar inputs (0 V to +5 V) or dual ±5 V supplies for bipolar inputs (±2.5 V). Key electrical parameters include a signal-to-noise ratio of 45 dB, total unadjusted error of ±1 LSB, and power dissipation of 50 mW. It provides parallel three-state data outputs and interfaces via standard microprocessor control signals.

Feature Summary

• Half-flash conversion technique eliminates the need for external clock generation.
• Built-in track-and-hold handles input signals with slew rates up to 1.6 V/µs.
• Supports both unipolar and bipolar input ranges through flexible reference configurations.
• Designed for direct interfacing with microprocessors using standard control signals.

Applications

• Digital signal processing systems requiring precise sampling intervals.
• Voice recognition and echo cancellation circuits.
• Adaptive filtering applications.
• High-speed data acquisition systems.

Procurement Notes

Verify the specific suffix KPZ corresponds to the Plastic Leaded Chip Carrier package option P-20A as defined in the ordering guide. Confirm that the K version temperature range of -40°C to +85°C aligns with the operational requirements of the target environment. Ensure compatibility with the required logic voltage levels before integration.

Selection Notes

Select this component when a fast conversion time under 700 ns is required without external timing circuitry. Choose the bipolar configuration if the application involves signals centered around zero volts. Consider the parallel interface requirements and the availability of sufficient address lines for memory-mapped access in the system design.

Part Context

The AD7821 serves as a high-speed successor to the AD7820, offering improved performance metrics including faster conversion times and higher signal bandwidth. It is fabricated using Linear Compatible CMOS technology, combining precision bipolar circuits with low-power CMOS logic to achieve efficient operation within the 8-bit ADC category.

Replacement Considerations

The AD7820 is a documented predecessor with slower specifications. Verify pinout compatibility and check if the reduced bandwidth of alternative devices meets the system's Nyquist criteria. No direct cross-manufacturer substitutes are confirmed in the provided documentation.