AD7777AR

Overview

The AD7777AR is a quad-channel, 10-bit successive approximation register (SAR) analog-to-digital converter manufactured by Analog Devices Inc. It operates within an ambient temperature range of -40°C to +85°C and utilizes a 28-lead SOIC package. The device features a parallel data interface and accepts single-ended analog inputs with a nominal supply voltage of 5 V. Key electrical specifications include a maximum differential nonlinearity of ±1 LSB, ensuring no missing codes, and a typical signal-to-noise ratio of 56 dB at full-scale input. Power consumption in normal mode is limited to 15 mA, while the power-down mode reduces current draw to 1.5 mA.

Feature Summary

• Simultaneous sampling capability for two channels via control register configuration
• Integrated track-and-hold amplifiers supporting high-frequency signal acquisition
• Configurable BUSY/INT output pin for flexible status monitoring or interrupt signaling
• Internal 2.0 V reference output providing bias voltage for analog inputs

Applications

• Digital signal processing systems requiring voice recognition or echo cancellation
• Adaptive filtering applications demanding precise dynamic performance
• Multi-channel data acquisition systems utilizing simultaneous sampling modes
• Microprocessor interfacing with DSP machines such as TMS320 or ADSP families

Procurement Notes

Verify the specific ordering suffix 'R' indicates the SOIC package variant when sourcing components. Confirm that the required operating temperature range aligns with the specified -40°C to +85°C limits for industrial environments. Ensure that the design accommodates the necessary decoupling capacitors for the REFIN pin to maintain specified performance levels during operation.

Selection Notes

Select this component for applications requiring four independent analog input channels with 10-bit resolution. Consider the parallel interface requirements and ensure the host system can manage the timing constraints for write and read cycles. Evaluate the need for simultaneous sampling features if channel synchronization is critical for the specific measurement application.

Part Context

The AD7777AR belongs to the AD7776/AD7777/AD7778 family of SAR ADCs from Analog Devices. This series provides scalable channel counts ranging from one to eight, sharing common architectural features such as the 10-bit resolution and parallel bus interface. The AD7777 specifically addresses designs needing four channels without the complexity of higher channel counts.

Replacement Considerations

The AD7777AN serves as a direct through-hole replacement offering identical electrical characteristics in a PDIP-28 package. Designers must account for the physical footprint differences between the surface-mount SOIC and the leaded PDIP variants when substituting components.