AD7948BRS

Overview

The AD7948BRS is a 12-bit multiplying digital-to-analog converter (DAC) from Analog Devices, housed in a 20-lead SSOP package. It features an 8-bit byte interface with separate MSB and LSB chip selects, enabling efficient data transfer. The device operates on a single +5 V supply (Normal Mode) or a +3.3 V to +5 V supply (Biased Mode). Key electrical specifications include ±0.5 LSB maximum relative accuracy, differential nonlinearity (DNL), and integral nonlinearity (INL). It delivers a typical power dissipation of 5 mW and achieves a fast output voltage settling time of 600 ns to 0.01% full-scale range.

Feature Summary

• 12-bit resolution with guaranteed monotonicity over temperature
• 0.5 LSB maximum INL and DNL for high precision
• Low power consumption: typically 5 mW at +5 V
• Fast settling time of 600 ns to 0.01% with external amplifier

Applications

• Battery-powered instrumentation
• Laptop computers
• Upgrades for all 754x series DACs in 5 V designs

Procurement Notes

Verify the specific ordering suffix against the manufacturer's current documentation to confirm pinout compatibility and temperature grade. The AD7948BRS denotes the industrial temperature range (-40°C to +85°C) and SSOP package. Ensure that system requirements align with the 8-bit parallel interface timing constraints defined in the datasheet.

Selection Notes

Select the AD7948BRS when an 8-bit byte-oriented interface is required for microprocessor integration, distinguishing it from the 12-bit parallel AD7945 and serial AD7943. Choose this component for applications requiring low glitch impulse (60 nV-s typ) and fast settling times. Verify that the system can accommodate the external reference input and current-output configuration necessitating an external operational amplifier.

Part Context

The AD7948 is part of the AD7943/AD7945/AD7948 family of fast 12-bit multiplying DACs. While sharing identical core DAC architecture and performance metrics with its siblings, the AD7948 is uniquely defined by its 8-bit byte interface logic. This allows for flexible data loading via CSMSB and CSLSB signals, optimizing bandwidth and bus utilization in systems where data is transmitted in byte-sized chunks.

Replacement Considerations

The AD7948 serves as a direct drop-in replacement for the industry-standard AD7548, offering superior speed and lower power consumption. For interface variations within the same package, the AD7945 (12-bit parallel) and AD7943 (serial) are functionally compatible alternatives if interface timing permits.