**The AD585AQ: A High-Performance Sample-and-Hold Amplifier for Precision Data Acquisition**
In the realm of precision data acquisition systems, the integrity of an analog signal at the moment of conversion is paramount. The process of digitizing a rapidly changing signal requires that the input to the analog-to-digital converter (ADC) be held perfectly stable during the conversion cycle; any deviation results in errors and degraded system performance. This critical function is performed by a Sample-and-Hold Amplifier (SHA), and among the most distinguished components in this category is the **AD585AQ from Analog Devices**.
The AD585AQ is a monolithic SHA specifically engineered to deliver **exceptional accuracy and speed**. It integrates a high-performance operational amplifier, a low-leakage hold capacitor, and all the necessary switching circuitry into a single chip. This high level of integration eliminates the need for external components and simplifies design-in, while ensuring optimized performance and reliability. Its primary role is to sample an analog voltage upon command and then hold that value constant with minimal decay, providing a stable signal for the ADC to digitize.
A key attribute of the AD585AQ is its **remarkably low droop rate**. The droop rate, which is the rate at which the held voltage decays over time due to capacitor leakage and bias currents, is a critical specification for precision applications. The AD585AQ achieves a typical droop rate of just **0.1 mV/ms**, ensuring that the voltage presented to the ADC remains virtually unchanged even during longer conversion periods. This is complemented by an **acquisition time to 0.01% of just 3 µs** for a 10V step, allowing it to rapidly capture and settle on fast-changing input signals.
Furthermore, the device excels in its **aperture characteristics**. The aperture time is the uncertain delay between the hold command and the actual opening of the switch, while aperture jitter is the variation in this time. Minimal jitter is absolutely essential for sampling high-frequency signals accurately. The AD585AQ exhibits very low aperture jitter, typically less than 500 ps, making it an excellent choice for high-speed, high-resolution data conversion systems where timing precision is non-negotiable.
The "AQ" suffix denotes a premium grade component, characterized by its extended industrial temperature range (-55°C to +125°C) and guaranteed specifications. This makes the AD585AQ **uniquely suited for demanding environments** such as military, aerospace, industrial automation, and high-end instrumentation. Whether deployed in radar systems, digital oscilloscopes, or precision test equipment, the AD585AQ provides the robust performance required for mission-critical applications.
**ICGOODFIND:** The AD585AQ stands as a benchmark in sample-and-hold technology, offering designers a complete, high-accuracy solution for stabilizing analog signals in precision data acquisition paths. Its integration of a hold capacitor, ultra-low droop rate, and fast acquisition time **ensures maximum performance from high-resolution ADCs**, solidifying its status as a go-to component for challenging engineering designs.
**Keywords:** Sample-and-Hold Amplifier, Precision Data Acquisition, Low Droop Rate, Fast Acquisition Time, Aperture Jitter
