**AD1674AR: A Comprehensive Technical Overview of the 12-Bit Analog-to-Digital Converter**

The **AD1674AR** from Analog Devices represents a significant milestone in the evolution of data acquisition systems. As a complete, **12-bit analog-to-digital converter (ADC)** with a **built-in sample-and-hold amplifier** and internal voltage reference, it integrates all critical components required for high-accuracy conversion into a single 28-pin package. This device has established itself as a robust and reliable solution for a wide array of demanding industrial, medical, and communications applications.

At its core, the AD1674AR employs a **successive approximation register (SAR)** architecture, which provides an optimal balance between speed, accuracy, and power consumption. It is capable of achieving a **100 kSPS (kilo-samples per second)** conversion rate, making it suitable for medium-speed signal processing tasks. The converter can be configured to accept a variety of input ranges, including the standard **±10 V, ±5 V, 0 to 10 V, and 0 to 20 V**, offering exceptional flexibility for interfacing with different sensor outputs and signal conditioning circuits.

A key feature of the AD1674AR is its high level of integration. Unlike earlier ADCs that required numerous external components, the AD1674AR includes an internal **+10.0 V voltage reference**, a precision buried Zener diode that is laser-trimmed for high accuracy and low temperature drift. This internal reference is fundamental to achieving the device's specified performance, ensuring stable and precise conversions over time and temperature variations. Furthermore, the integrated sample-and-hold amplifier accurately captures fast-changing analog signals, guaranteeing that the input voltage is held constant during the entire conversion process, which is critical for maintaining the **12-bit integral and differential nonlinearity (INL/DNL)**.

The device offers two interface modes: a standalone mode for simple system integration and a microprocessor-compatible mode for bus-based systems. Its digital output is presented in **straight binary format for unipolar inputs and offset binary for bipolar inputs**, simplifying data interpretation in both scenarios. Control logic is straightforward, managed through the **CE (Chip Enable), CS (Chip Select), and R/C (Read/Convert)** pins, allowing for easy interfacing with microprocessors and digital signal processors.

The AD1674AR is designed for performance and durability. It typically exhibits a **total harmonic distortion (THD)** of less than -80 dB and a **signal-to-noise ratio (SNR)** sufficient for high-fidelity digital reproduction of analog signals. Its operation is specified over the industrial temperature range (-40°C to +85°C), ensuring reliable performance in harsh environments.

**ICGOOFind:** The AD1674AR stands as a quintessential example of a highly integrated, precision data conversion solution. Its combination of a **built-in sample-and-hold**, a **high-accuracy internal reference**, and a **versatile input range** within a single IC package eliminates design complexity and reduces board space. For engineers developing systems requiring **medium-speed, high-accuracy 12-bit conversion**, the AD1674AR remains a compelling and trustworthy choice, blending proven architecture with robust performance.

**Keywords:**

1. **12-Bit Analog-to-Digital Converter (ADC)**

2. **Successive Approximation Register (SAR)**

3. **Built-in Sample-and-Hold**

4. **Internal Voltage Reference**

5. **100 kSPS**