AD974BRS

Overview

The AD974BRS is a four-channel, 16-bit analog-to-digital converter (ADC) data acquisition system manufactured by Analog Devices Inc. It operates from a single +5 V supply and supports throughput rates up to 200 kSPS. The device integrates an input multiplexer, a high-speed sampling ADC, and a +2.5 V reference. It accommodates analog input ranges of –10 V, 0 V to +4 V, or 0 V to +5 V. The component features a serial interface for efficient data transfer with minimal interconnects. It is housed in a 28-lead SSOP package and specified for operation between –40°C and +85°C.

Feature Summary

• Four single-ended analog input channels with integrated 4-to-1 multiplexer
• 16-bit resolution with 200 kSPS throughput rate
• Single +5 V supply operation with power-down mode reducing dissipation to 50 mW
• Supports internal or external 2.5 V reference sources

Applications

• Industrial process control systems requiring multi-channel data acquisition
• Portable instrumentation utilizing single-supply operation
• Battery-powered measurement devices leveraging low-power modes
• Data logging applications with serial interface requirements

Procurement Notes

Verify the specific grade (A or B) required for linearity and dynamic range specifications. Confirm the package type matches the design footprint, as the AD974 series includes DIP, SOIC, and SSOP variants. Ensure the selected part number corresponds to the desired temperature range and performance grade before ordering.

Selection Notes

Select the AD974BRS when a compact SSOP package is required for the application. Choose this model over other grades if the A-grade specifications for Integral Nonlinearity Error (–3.0 LSB) and Signal-to-(Noise+Distortion) (83 dB) are sufficient. Verify that the serial interface timing aligns with the host microcontroller capabilities.

Part Context

The AD974BRS belongs to the AD974 family of data acquisition systems. This family combines multiplexed inputs, ADC conversion, and reference generation on a single BiCMOS chip. Other variants include the AD974AN/BN (DIP) and AD974AR/BR (SOIC), offering different packaging options while maintaining identical electrical characteristics for their respective grades.

Replacement Considerations

Direct replacements within the same family include the AD974ARS (A-grade SSOP) or AD974BR (B-grade SOIC). Ensure the substitute maintains the required package outline and pin compatibility. Verify that the thermal resistance and power dissipation limits of the alternative package meet the system's thermal design constraints.

FAQ

What analog input voltage ranges does the AD974BRS support?

The device supports three input ranges: –10 V (bipolar), 0 V to +4 V, and 0 V to +5 V (unipolar).

How is the data clock configured for serial output?

The EXT/INT pin determines the clock source. Tying it low enables the internal data clock, while tying it high allows synchronization with an external clock signal applied to the DATACLK pin.

What is the maximum power dissipation in power-down mode?

When the PWRD pin is set to a logic HIGH, the power consumption is reduced to a maximum of 50 mW.