AD7911ARMZ

Overview

The AD7911ARMZ is a dual-channel, 10-bit successive approximation analog-to-digital converter (ADC) manufactured by Analog Devices Inc. It operates from a single 2.35 V to 5.25 V supply and supports throughput rates up to 250 kSPS. The device features an on-chip track-and-hold amplifier capable of handling input frequencies exceeding 6 MHz. Power consumption is typically 4 mW at 250 kSPS with 3 V supplies and 13.5 mW with 5 V supplies. It includes a flexible serial interface compatible with SPI, QSPI, MICROWIRE, and DSP standards. The component is housed in an 8-lead MSOP package and functions within a temperature range of -40°C to +85°C.

Feature Summary

• Dual-channel architecture with internal multiplexing for sequential conversion
• Low power operation with dedicated standby mode reducing current to 1 μA maximum
• Integrated track-and-hold amplifier supporting wide bandwidth inputs
• Standard serial interface allowing direct connection to microprocessors and DSPs

Applications

• Battery-powered personal digital assistants
• Medical instrumentation systems
• Mobile communications devices
• Data acquisition systems
• High-speed modems

Procurement Notes

Verify the specific ordering suffix against official documentation to confirm package type and temperature grade. Ensure compatibility with system voltage requirements between 2.35 V and 5.25 V. Confirm that the MSOP-8 footprint matches the design layout. Check for RoHS compliance status if required by local regulations. Validate signal integrity for the serial interface connections.

Selection Notes

Select this component when a low-cost, low-power solution is required for applications needing two single-ended analog inputs. The 10-bit resolution is suitable for general-purpose data acquisition where high precision is not critical. Consider the external reference derived from VDD, which simplifies design but limits dynamic range to the supply voltage. Evaluate the serial clock speed requirements to ensure the desired throughput rate is achievable within the system timing constraints.

Part Context

The AD7911 is part of the AD7911/AD7921 family of high-speed, low-power ADCs. While the AD7911 offers 10-bit resolution, the companion AD7921 provides 12-bit resolution with similar performance characteristics. Both share identical pinouts and operational modes, facilitating easy upgrades or downgrades in design based on accuracy needs. The series is designed for space-constrained portable applications requiring efficient power management.

Replacement Considerations

The AD7921ARMZ serves as a higher-resolution alternative within the same package and family. Other generic 10-bit SAR ADCs may require significant circuit redesign due to differences in interface protocols, pin configurations, or power supply requirements.