AD7948BR

Overview

The AD7948BR is a 12-bit multiplying digital-to-analog converter (DAC) featuring an 8-bit byte interface. It operates from a single +5 V supply in Normal Mode or a +3.3 V to +5 V supply in Biased Mode. The device guarantees ±0.5 LSBs integral and differential nonlinearity with a typical power consumption of 5 mW. Key performance metrics include a 60 nV-s glitch impulse and a settling time of 600 ns to 0.01% when used with the AD843 amplifier. It utilizes a segmented architecture with R-2R ladder switching for constant input resistance.

Feature Summary

• 12-bit resolution with guaranteed ±0.5 LSB INL and DNL
• 8-bit byte interface with CSMSB, CSLSB, WR, and LDAC control signals
• Low power consumption: 5 μA max supply current (typical 5 mW)
• Fast settling time of 600 ns to 0.01% full-scale range

Applications

• Battery-powered instrumentation
• Laptop computer systems
• Upgrades for legacy 754x series DAC designs

Procurement Notes

Verify the specific package variant, as the AD7948BR denotes the SOP (Small Outline Package) option. Confirm temperature grade requirements; the B-grade version supports -40°C to +85°C. Ensure design compatibility with the 8-bit byte interface logic levels and timing constraints defined in the datasheet before finalizing procurement.

Selection Notes

Select the AD7948BR when an 8-bit parallel data bus is available, reducing pin count compared to the 12-bit parallel AD7945. Choose this model over the serial AD7943 if higher throughput is required without serial clock overhead. Verify that the application requires the specific 8-bit byte loading sequence supported by the CSMSB/CSLSB pins.

Part Context

The AD7948 is part of the AD7943/AD7945/AD7948 family of fast 12-bit multiplying DACs. While functionally identical in conversion accuracy and analog performance, it differs from the AD7943 (serial interface) and AD7945 (12-bit parallel interface) primarily in its digital input structure. This allows designers to select the interface topology that best matches their system's microcontroller or FPGA capabilities.

Replacement Considerations

The AD7948BR serves as a direct replacement for the industry-standard AD7548 in 5 V designs, offering superior speed and lower power consumption. When replacing older components, verify that the new component's 8-bit byte interface timing aligns with the existing system logic.