**High-Performance Data Acquisition with the AD7708BRZ 24-Bit Sigma-Delta ADC**

In the realm of precision measurement, the integrity of the analog-to-digital conversion process is paramount. The **AD7708BRZ from Analog Devices** stands as a pinnacle of high-resolution data acquisition, engineered to deliver exceptional performance in demanding applications. This 24-bit sigma-delta (Σ-Δ) ADC is specifically designed to convert low-level, low-frequency signals directly from sensors with unparalleled accuracy and minimal external circuitry.

The core of its performance lies in the **sigma-delta modulation technique**. Unlike successive approximation register (SAR) ADCs, the Σ-Δ architecture oversamples the input signal and uses noise shaping to push quantization noise out of the baseband. This results in extremely high effective resolution and outstanding noise performance within the target bandwidth. The AD7708BRZ capitalizes on this, offering a truly **24-bit no-missing-codes performance**, ensuring that every least significant bit (LSB) is meaningful and contributes to an accurate digital representation of the analog input.

A key feature that makes the AD7708BRZ exceptionally versatile is its **fully differential eight-channel input multiplexer**. This allows a single device to interface with multiple sensors, such as thermocouples, RTDs, strain gauges, or pressure transducers, simplifying system design and reducing component count. The differential inputs are crucial for rejecting common-mode noise, which is a common challenge in industrial environments, thereby preserving signal fidelity.

Furthermore, the device integrates a **programmable gain amplifier (PGA)** with gains from 1 to 128. This allows small sensor signals, often in the millivolt range, to be amplified to the optimal level for the ADC's modulator, maximizing the dynamic range and eliminating the need for external precision amplifiers. This integration, combined with an on-chip digital filter, provides a complete analog front-end solution.

The digital filter is not merely a low-pass filter; it is a **sinc³ (sinc cubed) filter** that provides a sharp roll-off and excellent rejection of line frequency (50/60 Hz) interference. The output data rate and filter notch frequency are programmable, enabling designers to tailor the trade-off between resolution (noise) and channel throughput speed for their specific application, whether it's a slow-scale weighing system or a multi-channel data logger.

Communication with a microcontroller is streamlined through a serial interface (SPI/QSPI™/MICROWIRE™/DSP compatible), making it easy to integrate into modern embedded systems. The AD7708BRZ operates on a single supply voltage, enhancing its suitability for portable, battery-operated instruments.

**ICGOO**

In summary, the AD7708BRZ is a cornerstone component for engineers building high-precision measurement systems. Its combination of **high resolution, integrated multiplexing, programmable gain, and exceptional noise performance** makes it an indispensable solution for applications across industrial process control, scientific instrumentation, and medical equipment.

**Keywords: Sigma-Delta ADC, 24-Bit Resolution, Programmable Gain Amplifier (PGA), Data Acquisition, Low-Frequency Measurement.**