AD7938BSUZ

Overview

The AD7938BSUZ is a high-speed, low-power 12-bit successive approximation register (SAR) analog-to-digital converter manufactured by Analog Devices Inc. It features eight analog input channels with an integrated channel sequencer and operates from a single 2.7 V to 5.25 V power supply. The device achieves throughput rates up to 1.5 MSPS with a differential track-and-hold amplifier capable of handling input frequencies up to 50 MHz. Key specifications include a maximum power dissipation of 6 mW at 3 V and 13.5 mW at 5 V, an on-chip 2.5 V reference, and a full shutdown mode consuming 2 µA maximum current. It utilizes a high-speed parallel interface compatible with 3 V or 5 V processor systems via the VDRIVE function.

Feature Summary

• Eight analog input channels with software-configurable sequencing for single-ended, fully differential, or pseudo-differential inputs.
• Integrated accurate 2.5 V internal voltage reference with options for external overdrive.
• VDRIVE function enabling direct connection to independent 3 V or 5 V processor logic levels.
• No pipeline delay architecture with precise sampling control via CONVST falling edge.

Applications

• Industrial process control systems requiring multi-channel data acquisition.
• Portable instrumentation utilizing single-supply operation and low power consumption.
• Data acquisition modules interfacing with microprocessors or DSPs via parallel interfaces.

Procurement Notes

Verify the specific package variant required, as the AD7938 series is available in both LFCSP and TQFP configurations. Confirm that the ordering suffix matches the desired physical footprint and lead frame material. Ensure compatibility with the system's voltage domains, particularly regarding the VDD and VDRIVE supply requirements specified in the datasheet.

Selection Notes

Select the AD7938BSUZ when 12-bit resolution and 1.5 MSPS throughput are required for multi-channel applications. Consider the AD7939 if 10-bit resolution is sufficient for cost reduction. Evaluate the need for the internal 2.5 V reference versus an external precision reference based on system noise requirements and board space constraints.

Part Context

The AD7938BSUZ belongs to the AD7938/AD7939 family of 12-bit and 10-bit parallel ADCs. This series is designed for applications demanding high speed and low power within a compact form factor. The BSUZ suffix typically denotes the TQFP-32 package variant, distinguishing it from the LFCSP versions available in the same product line.

Replacement Considerations

The AD7938BSUZ-6 is listed as a parameter-equivalent alternative within the manufacturer's portfolio. Verify pinout and electrical specifications against the primary datasheet before substitution.