AD7805BRS

Overview

The AD7805BRS is a quad 10-bit digital-to-analog converter (DAC) from Analog Devices, housed in a 28-lead Shrink Small Outline Package (SSOP). It features parallel data loading capabilities and operates on a single +3.3 V to +5 V power supply. The device integrates an on-chip bandgap reference outputting approximately 1.23 V. Each of the four DAC channels includes double-buffered data registers and an internal Sub-DAC for transfer function shifting around a configurable VBIAS point. Control features include system-wide or individual channel standby and power-down modes, asynchronous clear functions, and support for both two's complement and offset binary input coding schemes.

Feature Summary

• Quad 10-bit resolution with parallel load interface
• Integrated 1.23 V bandgap reference output
• On-chip Sub-DAC for individual channel transfer function adjustment
• Dual buffered DAC registers for simultaneous analog updates via LDAC

Applications

• Optical disk drives
• Process control and voltage setpoint control systems
• Instrumentation and communication equipment
• Trim potentiometer replacement circuits
• Automatic calibration systems

Procurement Notes

Verify the package designation RS-28 corresponds to the required 28-lead SSOP footprint. Confirm that the B grade accuracy specifications meet the application requirements relative to the C grade alternative. Ensure the parallel interface timing constraints align with the host controller's write pulsewidth and setup/hold times.

Selection Notes

Select the AD7805BRS when a parallel interface is preferred over serial options like the AD7804. Choose this model if the design requires four independent 10-bit outputs within a compact SSOP form factor. Verify that the +3.3 V to +5 V supply range matches the system power rails and that the 2 kΩ minimum load resistance requirement can be satisfied by the downstream circuitry.

Part Context

The AD7805BRS belongs to the AD780x family of low-power CMOS DACs. It serves as the parallel-loading counterpart to the serial-loaded AD7804. While the AD7804 utilizes SDIN, CLKIN, and FSIN lines, the AD7805 employs DB0-DB9 data inputs controlled by WR, CS, and address pins A0-A2. This distinction allows designers to choose between serial bus efficiency and parallel data throughput based on system architecture.

Replacement Considerations

The AD7805BR is a pin-compatible alternative in the standard SOIC-28 package. The AD7805BN offers a 28-lead DIP option. For applications requiring octal channels, the AD7809 provides eight parallel DACs in a TQFP package.