AD7944BCPZ-RL7

Overview

The AD7944BCPZ-RL7 is a 14-bit, 2.5 MSPS successive approximation analog-to-digital converter (ADC) from Analog Devices. It features a pseudo-differential input range of 0 V to VREF with VREF up to 5.0 V. The device operates on AVDD/DVDD at 2.5 V and VIO between 1.8 V and 2.7 V. Power dissipation is 28 mW with the internal reference or 15.5 mW with an external reference at 2.5 MSPS. Key performance metrics include an INL of ±1.0 LSB maximum, DNL of ±0.9 LSB maximum, and SNR of 84.5 dB with an external reference. It utilizes a 20-lead LFCSP package and supports SPI/Microwire interfaces.

Feature Summary

• Features two conversion modes: Turbo mode for maximum throughput without power-down and Normal mode for reduced power consumption proportional to throughput.
• Includes an integrated 4.096 V bandgap reference with low temperature drift or supports external references up to 5.0 V via the REF pin.
• Supports daisy-chaining multiple ADCs on a single serial bus using the SDI input in chain mode, providing optional busy indicator functionality.
• Offers a versatile digital interface compatible with 1.8 V, 2.5 V, and 2.7 V logic levels through a separate VIO supply.

Applications

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

Procurement Notes

Verify the specific ordering suffix RL7 indicates reel packaging when sourcing this component. Confirm that the BC grade meets the required operating temperature range of -40°C to +85°C for your application environment. Ensure compatibility with the 20-lead LFCSP footprint during PCB layout planning. Check for RoHS compliance status as per the manufacturer's current documentation before finalizing procurement orders.

Selection Notes

Select the AD7944BCPZ-RL7 when a 14-bit resolution and high sampling rate are required alongside low power consumption. Consider the internal reference if board space is limited, otherwise use an external reference for optimal SNR performance. Evaluate the need for daisy-chaining capabilities if multiple channels are present. Ensure the host system supports the required 3-wire or 4-wire serial interface protocols for data retrieval.

Part Context

This component belongs to the PulSAR family of ADCs from Analog Devices. It is pin-for-pin compatible with the AD7985 (16-bit) and AD7986 (18-bit), allowing for potential design upgrades without changing the physical footprint. The device shares similar architectural features with other SAR ADCs in the series but offers specific trade-offs between resolution, speed, and power dissipation.

Replacement Considerations

The AD7985 and AD7986 are pin-for-pin compatible alternatives offering higher resolutions of 16 bits and 18 bits respectively. These substitutes maintain the same package and interface characteristics while potentially impacting power consumption and throughput specifications.