This is the only analog term you should know
Sampling rate
The sampling rate is the number of sampling processes performed per second in an A / D converter that converts an analog signal into a digital signal. Also called sample rate, sample rate, or sample rate. The unit is sample / second (sps) or Hz.
A / D converters have two crucial functions. One is resolution. The other is this sample rate. The resolution represents the precision of the conversion in the direction of the voltage axis (vertical axis) and the sample rate represents the precision of the conversion in the direction of the time axis (horizontal axis). Therefore, the higher the performance (the higher the performance), the better the performance.
Input signals of fs / 2 or less can be sampled
Higher sample rates allow faster analog input signals to be converted to digital values. However, there is a limit to the frequency of the analog input signal that can be converted. If the sampling frequency is fs, the frequency that can be sampled is fs / 2. Below this frequency, it is possible to restore the original analog input signal after sampling. This relationship is called the sampling theorem (sampling theorem) and the frequency of fs / 2 is called the Nyquist frequency.
What sample rate do you need? It depends on the application the A / D converter is applied to. For example, tens of k to several M samples / sec (Hz) for audio equipment, tens to hundreds of M samples / sec (Hz) for audio processing equipment. pictures and tens to several G samples for communication equipment. The A / D converter is used for / sec (Hz), several k to several M samples / sec (Hz) for high precision measuring instruments, and several tens of M to several G samples / sec (Hz) for measuring instruments. Of high speed.
Currently, as a high-speed A / D converter, an IC with a high sampling rate of several Gsample / sec is marketed. For example, Texas Instruments (TI) “ADC12D1800RF”. The resolution is 12 bits. It integrates two A / D converters with a high sampling frequency of 1.8 Gsample / sec. By interleaving (time division) operation, it can be used as a 3.6 Gsample / sec A / D converter, and also as a dual A / D converter operating at 1.8 Gsample / sec. For broadband communication equipment, radar equipment, test / measurement equipment, etc.
