AD7248ABR

Overview

The AD7248ABR is a monolithic 12-bit voltage output digital-to-analog converter (DAC) from Analog Devices, part of the DACPORT family. It integrates an output amplifier and a buried Zener voltage reference on a single CMOS chip. The device features an 8-bit parallel data bus with a double-buffered interface logic structure, requiring two write operations to load the full 12-bit word. It operates from supply voltages ranging from +10.8 V to +16.5 V for VDD and -10.8 V to -16.5 V for VSS. Key performance metrics include a settling time of 7 µs to within ±1/2 LSB, a typical power consumption of 65 mW in single-supply mode, and a relative accuracy grade of ±1/2 LSB for the 'B' variant.

Feature Summary

• 12-Bit LC2MOS DAC with integrated output amplifier and internal 5V buried Zener reference
• Parallel loading structure: 8-bit wide data bus loaded in two separate write cycles (MSB nibble and LSB byte)
• Extended linearity grade: ±1/2 LSB maximum relative accuracy
• Fast interface timing with typical 30 ns data setup time

Applications

• Microprocessor-controlled analog signal generation
• Industrial process control systems requiring high-speed updates
• Test and measurement equipment needing precise voltage references
• Multi-channel data acquisition systems utilizing double-buffered updates

Procurement Notes

Verify the specific suffix 'BR' indicates the SOIC-20 surface mount package option when sourcing. Confirm that the 'A' or 'B' designation matches the required linearity accuracy grade (±3/4 LSB vs ±1/2 LSB). Ensure the operating environment falls within the specified commercial temperature range of –40°C to +85°C. Check for RoHS compliance status as manufacturing processes may vary by production batch.

Selection Notes

Select the AD7248ABR over the AD7245A variant if the system utilizes an 8-bit microprocessor data bus, as it simplifies interfacing by accepting data in two writes rather than a single 12-bit parallel load. Choose this component for applications requiring dual-supply operation to achieve bipolar output ranges or improved unipolar settling characteristics near zero volts. Consider the SOIC-20 package constraints regarding thermal dissipation and board space compared to DIP options.

Part Context

The AD7248A is an enhanced version of the industry-standard AD7248, offering improvements such as operation from 12 V to 15 V supplies, faster interface times, and better full-scale variation with VDD. It belongs to the DACPORT series, which combines precision bipolar circuits with low-power CMOS logic in the LC2MOS process. This integration reduces component count and increases reliability compared to multichip designs.

Replacement Considerations

The AD7245ABR is a functional alternative but requires a 12-bit parallel interface instead of the 8-bit split loading structure. The standard AD7248A (without the B suffix) offers ±3/4 LSB accuracy instead of ±1/2 LSB. For military specifications, parts processed to MIL-STD-883 Class B are available by adding /883B to the part number.