AD7805CR

Overview

The AD7805CR is a quad 10-bit digital-to-analog converter (DAC) from Analog Devices, featuring parallel data loading capabilities. It operates on a single +3.3 V to +5 V power supply and incorporates an on-chip bandgap reference outputting 1.23 V nominal. The device contains four independent DAC channels with double-buffered data registers, allowing simultaneous analog updates via the LDAC input. Each channel includes a Sub DAC for transfer function shifting around a configurable VBIAS point. Static performance specifications include a maximum relative accuracy of 3 LSBs and a gain error of 3% FSR. The component supports system standby and power-down modes to minimize current consumption.

Feature Summary

• Quad 10-bit resolution with parallel load interface
• Integrated 1.23 V bandgap reference output
• On-chip control registers for individual channel management
• Double-buffered DAC registers for simultaneous updates

Applications

• Optical disk drives
• Process control and voltage setpoint control
• Instrumentation and communication systems
• Automatic calibration circuits

Procurement Notes

Verify the package type corresponds to the 'R' suffix, indicating a 28-lead Small Outline IC (SOIC). Confirm the temperature range matches the commercial grade specification of -40°C to +85°C. Ensure the static accuracy requirement aligns with the C Grade rating of ±3 LSB max relative accuracy. Check that the design accommodates the specified power supply range of 3.3 V to 5.5 V.

Selection Notes

Select the AD7805 variant specifically when parallel data inputs are required; the AD7804 provides serial loading instead. Consider the AD7809 if octal (eight-channel) configuration is needed rather than quad. Evaluate the internal reference against external precision requirements, as the on-chip REFOUT has a typical temperature coefficient of -100 ppm/°C. Verify that the 10-bit resolution meets the application's dynamic range needs.

Part Context

The AD7805 is part of the AD7804/AD7805/AD7808/AD7809 family of CMOS 10-bit DACs. This family differentiates by channel count (quad vs. octal) and interface type (serial vs. parallel). The AD7805 specifically bridges the gap between the serial AD7804 and the higher-density octal variants, offering parallel access for simplified bus interfacing in multi-channel applications.

Replacement Considerations

The AD7804BR serves as a functional substitute if the system can accommodate serial SPI-like loading instead of parallel buses. For applications requiring more channels, the AD7809BST offers an octal parallel configuration in a TQFP package.