In industrial automation, instrumentation, medical devices, and power-quality monitoring systems, analog-to-digital converters (ADCs) play a central role in signal acquisition. An ADC not only determines the precision of each measurement—it also directly affects system synchronization, noise immunity, and the overall stability of the data path. As modern industrial systems continue to demand higher speed, more channels, and better synchronized sampling, choosing between different ADC architectures, input structures, and channel counts has become a crucial step in system design.

Analog Devices’ SAR ADC portfolio spans compact multi-channel MUX-SAR devices, higher-precision MUX-SAR converters, and ±10 V industrial-grade simultaneous-sampling ADCs. This guide compares the architecture features and application scenarios of the AD7689BCPZ, AD7699BCPZ, and AD7606BSTZ to help designers select the device best suited for their system requirements.

Parameter Comparison

Application Analysis

AD7689BCPZ

AD7689BCPZ is designed for general multi-channel acquisition tasks where strict synchronization is not required. Its simple architecture and flexible input options make it easy to integrate into cost-sensitive systems. In applications involving diverse sensors, moderate sampling rates, and standard precision requirements, the AD7689 maintains stable performance with minimal design overhead.

Common applications include environmental monitoring modules, industrial I/O boards, small process-acquisition units, and mainstream automation equipment. These scenarios make AD7689 a practical and widely applicable baseline choice for general-purpose data acquisition.

AD7699BCPZ

Building on the same MUX-SAR foundation, AD7699BCPZ serves applications that demand better signal fidelity and more stable measurement results. Without requiring major system redesigns, it delivers higher accuracy, lower noise, and better handling of small-signal variations or wide dynamic-range inputs—making it a natural upgrade path from AD7689.

It is well suited for medical diagnostics, high-end test instruments, precision measurement tools, and industrial systems requiring tight linearity, strong noise performance, and higher consistency. When general-purpose accuracy is no longer sufficient, AD7699 becomes the preferred alternative.

AD7606BSTZ

AD7606BSTZ targets industrial applications where simultaneous sampling and robust noise performance are essential. Its architecture allows all eight channels to sample at the exact same moment, ensuring accurate correlation of multi-phase or multi-node signals—something MUX-SAR devices cannot achieve. Combined with its ±10 V input capability and strong EMI tolerance, it performs reliably in demanding electrical environments.

Typical applications include motor-control systems, power-grid monitoring, power-quality analysis, and multi-phase power-conversion front ends. Wherever synchronized sampling and strong industrial robustness are key design requirements, the AD7606 provides a dependable solution.

Design Considerations

Input Path Design

Because AD7689 and AD7699 rely on a multiplexed sampling structure, the front-end driver must settle quickly after each channel switch to avoid accuracy loss caused by insufficient settling time. In contrast, AD7606 uses independent sample-and-hold circuits for each channel, shifting design focus toward channel consistency and clean conditioning of each input path.

Noise Immunity

AD7606 inherently provides stronger common-mode rejection and higher tolerance to industrial-site interference, allowing it to maintain stable output under harsh EMI conditions. Meanwhile, AD7689 and AD7699 require more careful PCB routing, grounding, and power isolation strategies to preserve measurement integrity in noisy environments.

Layout and Ground Planning

MUX-SAR devices benefit from stricter separation between analog and digital regions to avoid switching-related disturbances. With AD7606, layout priorities differ slightly: designers should focus on symmetrical channel routing and consistent reference paths to maintain synchronous performance across all channels.

System Suitability

AD7689 offers the least integration overhead and suits mass-production or general-purpose systems.

AD7699 demands cleaner reference and power rails due to its higher accuracy.

AD7606 requires disciplined design practices for industrial synchronous systems, including resistance to transients and EMI, as well as highly consistent PCB layout.

Replacement & Migration Guidance

AD7689 ↔ AD7699

These two devices share a highly similar architecture and interface, making AD7699 a straightforward drop-in upgrade when higher precision is needed without modifying the analog front end.

AD7689 ↔ AD7606

Migrating from a MUX-SAR device like AD7689 to the simultaneous-sampling AD7606 requires changes to the sampling strategy and redesigned front-end conditioning. This path is appropriate when transitioning from general monitoring to applications that require channel-level synchronization, such as motor control or power-quality measurement.

AD7699 ↔ AD7606

Although the two can replace each other in terms of function, their underlying sampling architectures differ significantly. As a result, PCB layout and the signal chain must be redesigned. This migration is typical when extending a high-precision system into multi-phase synchronous measurement or more demanding industrial scenarios.

AD7689, AD7699, and AD7606 each offer distinct architectural strengths and environmental adaptability, providing a clear selection path for data-acquisition systems of varying complexity. From conventional control setups to demanding industrial environments, these devices strike a reliable balance among precision, synchronization, and noise immunity, giving designers greater flexibility when scaling system performance or enhancing measurement quality.

Key Takeaways

AD7689 = General-purpose acquisition

AD7699 = High-precision signal chain

AD7606 = Industrial-grade synchronous sampling

WIN SOURCE stocks all three ADC models and provides technical support throughout design, validation, and mass production. Visit WIN SOURCE for real-time inventory, lead-time updates, and alternative recommendations to keep your project on schedule.