AD7944BCPZ

Overview

The AD7944BCPZ is a 14-bit, 2.5 MSPS PulSAR analog-to-digital converter (ADC) manufactured by Analog Devices Inc. It features a successive approximation architecture with pseudo-differential analog inputs ranging from 0 V to VREF. The device operates with AVDD and DVDD at 2.5 V, BVDD at 5 V, and a digital interface voltage (VIO) of 1.8 V to 2.7 V. Key performance metrics include an SNR of 84 dB with the internal reference and 84.5 dB with an external reference. Power dissipation is 28 mW at 2.5 MSPS using the internal reference and 15.5 mW with an external reference. The component is housed in a 20-lead LFCSP package and supports operation between -40°C and +85°C.

Feature Summary

• Features two conversion modes: Turbo mode for maximum throughput up to 2.5 MSPS without power-down, and Normal mode for reduced power consumption at up to 2.0 MSPS.
• Includes an on-chip 4.096 V bandgap reference with low temperature drift or supports external references up to 5.0 V via the REF pin.
• Supports versatile serial interfaces compatible with SPI, QSPI, Microwire, and DSP standards, allowing daisy-chaining of multiple ADCs via the SDI input.

Applications

• Battery-powered equipment
• Communications systems
• Automatic test equipment (ATE)
• Data acquisition systems
• Medical instruments

Procurement Notes

Verify the specific ordering suffix against the manufacturer's current datasheet to ensure correct packaging and tape-and-reel specifications. Confirm that the procurement channel provides valid traceability documentation. Check for RoHS compliance status as indicated in the latest product release notes. Ensure the supplier is authorized to prevent counterfeit components. Validate that the delivered part matches the exact AD7944BCPZ designation regarding temperature grade and package type.

Selection Notes

Select this component when a single-channel, high-resolution SAR ADC is required with low power consumption. Choose the internal reference configuration for simplified design if strict accuracy requirements are met by the ±10 ppm/°C drift. Opt for the external reference option if higher dynamic range or lower noise is critical for the application. Consider the 20-lead LFCSP package constraints for PCB layout and thermal management. Ensure the host system supports the required 1.8 V to 2.7 V logic levels for the serial interface.

Part Context

The AD7944 belongs to the Analog Devices PulSAR family of 14-, 16-, and 18-bit ADCs. It is pin-for-pin compatible with the AD7985 (16-bit) and AD7986 (18-bit), facilitating easy upgrades in resolution without redesigning the PCB. This compatibility allows designers to scale performance within the same footprint while maintaining identical interface and pinout configurations.

Replacement Considerations

The AD7985 and AD7986 are direct pin-for-pin replacements offering higher resolution (16-bit and 18-bit respectively). Designers should verify that the increased resolution meets system requirements and that the slightly different power characteristics are acceptable within the existing power budget.