**AD7945BR: A 14-Bit, 8-Channel SAR ADC for Precision Data Acquisition Systems**

In the realm of precision data acquisition, the choice of Analog-to-Digital Converter (ADC) is paramount. It serves as the critical bridge between the analog physical world and the digital domain of processing and analysis. The **AD7945BR from Analog Devices** stands out as a premier solution, engineered to deliver high accuracy, flexibility, and robust performance in demanding applications. This 14-bit, 8-channel successive approximation register (SAR) ADC integrates key components to form a complete data acquisition system on a single chip.

At its core, the AD7945BR boasts **14-bit resolution with no missing codes**, ensuring high-precision digitization of analog signals. Its SAR architecture is chosen for a decisive advantage: **deterministic latency and high-speed performance**. Unlike sigma-delta (ΔΣ) ADCs that require filter settling time, the SAR ADC provides an accurate conversion result immediately after the acquisition period, making it ideal for applications requiring rapid control loops or multiplexed systems. With a throughput of up to 250 kSPS, it effectively handles a wide range of medium-speed signals.

A significant feature of this converter is its **high level of integration**. The inclusion of an 8-channel low-noise multiplexer (MUX) allows a single ADC to sequentially sample multiple sensor inputs, dramatically simplifying board design and reducing the overall component count. Furthermore, the device incorporates a low-drift, precision 2.5 V reference and a versatile reference buffer. This integrated reference enhances overall system accuracy by minimizing errors associated with external component drift and temperature variations. For designs requiring an external reference, the buffer can be configured to support that flexibility.

The AD7945BR is designed for ease of use and system compatibility. It features a simple SPI-compatible serial interface that connects seamlessly to a vast array of microcontrollers, DSPs, and FPGAs. Its operation is optimized for low power consumption, typically drawing just 6.5 mW at 250 kSPS, making it suitable for portable and battery-powered instruments. The device operates from a single 2.5 V to 5.5 V supply, adding to its design versatility.

**Typical applications** that benefit from the AD7945BR's combination of precision and integration include:

* **Industrial Control and Automation:** PLC systems, multi-channel sensor monitoring.

* **Medical Instrumentation:** Patient monitoring, portable diagnostic equipment.

* **Test and Measurement Equipment:** Data loggers, optical and spectrum analyzers.

* **Power Line Monitoring:** Multi-phase power and energy measurement systems.

**ICGOODFIND:** The AD7945BR is a highly integrated, precision SAR ADC that **combines high accuracy, multi-channel capability, and system-level components** into a single package. It eliminates the traditional design complexities of sourcing and matching external references and multiplexers, offering engineers a reliable, high-performance, and simplified path to building advanced data acquisition systems.

**Keywords:** 14-Bit Resolution, SAR ADC, 8-Channel Multiplexer, Integrated Voltage Reference, Precision Data Acquisition