AD7921ARMZ-REEL7

Overview

The AD7921ARMZ-REEL7 is a dual-channel, 12-bit successive approximation analog-to-digital converter (ADC) manufactured by Analog Devices Inc. It operates from a single supply voltage ranging from 2.35 V to 5.25 V and supports throughput rates up to 250 kSPS. The device features an internal track-and-hold amplifier with a wide input bandwidth capable of handling frequencies exceeding 6 MHz. Power consumption is specified at a maximum of 20 mW under operational conditions. The component utilizes a flexible serial interface compatible with SPI, QSPI, MICROWIRE, and DSP standards, housed in an 8-lead MSOP package.

Feature Summary

• Dual-channel architecture with integrated track-and-hold amplifier for simultaneous sampling applications
• Internal reference derived directly from the power supply to maximize dynamic input range
• Flexible serial interface supporting multiple standard protocols including SPI and MICROWIRE
• Low power operation with dedicated standby mode reducing current consumption significantly

Applications

• Battery-powered systems such as personal digital assistants and mobile communications devices
• Medical instruments requiring precise signal acquisition
• Instrumentation and control systems utilizing data acquisition architectures
• High-speed modems and optical sensor interfaces

Procurement Notes

Verify the specific ordering suffix REEL7 corresponds to the tape and reel packaging configuration required for automated assembly processes. Confirm that the A Grade temperature rating meets the environmental operating requirements of the target application. Ensure compatibility with the host microprocessor's logic voltage levels within the specified 2.35 V to 5.25 V range.

Selection Notes

Select this component when a dual-channel solution with 12-bit resolution is required at high speeds. Compare against the AD7911 if 10-bit resolution suffices, as it shares similar pinouts and functionality. Evaluate the power-down mode capabilities against system duty cycles to optimize battery life. Consider the MSOP package dimensions for PCB layout constraints relative to alternative packages like TSOT.

Part Context

This part belongs to the AD7911/AD7921 family of low-power, high-speed ADCs from Analog Devices. The AD7921 specifically denotes the 12-bit resolution variant, while the AD7911 offers 10-bit resolution. Both share identical pin configurations and operational characteristics, differing primarily in conversion accuracy and resulting dynamic performance metrics such as Signal-to-Noise Ratio.

Replacement Considerations

The AD7911ARMZ-REEL7 serves as a functional substitute within the same family, offering 10-bit resolution instead of 12-bit. Verify that the reduced resolution meets the system accuracy requirements before substitution. Other members of the AD79xx series may require pinout or software interface adjustments.