What Is an ADC?

An ADC (analog-to-digital converter) transforms an analog electrical signal — such as a voltage or current level — into a digital representation. This allows digital systems to analyze, store and process data.

To convert an analog input to a digital output, the circuit samples the analog amplitude at regular time intervals, then transforms the sampled data into binary numbers made up of 0 and 1. The resulting bits represent the occurrence of the analog event.

The control logic oversees the ADC's sampling and conversion processes. It may include features for calibration and error correction.

The ADC's sampling rate, or speed, determines the frequency of the analog signal it can accurately capture. A high sampling rate results in less distortion, or aliasing, in the reconstructed signal.

Another consideration is the amount of power the ADC consumes while operating. This is an important factor for battery-powered or energy-efficient devices.

ADCs can be deployed physically as hardware appliances or virtually as software running on x86 servers. In addition to providing application load balancing, they offer security features, including firewall and intrusion detection. They can also prevent DDoS attacks by blocking a sudden influx of traffic from reaching overloaded servers.

Some ADCs come with a web application firewall (WAF), which protects against Structured Query Language injections, cookie poisoning and cross-site scripting. They can also terminate SSL/TLS tunneling and block incoming traffic to DNS servers, protecting against DDoS attacks. In some cases, they can also help detect and prevent SQL injections.