In many systems, measurements of various physical, correct measurement is reduced to measuring voltage. There is a wide range of transducers that convert values such as temperature or the intensity of the light tension. What is the voltage measurement? In a large simplification, in order to measure its value is to compare it with a known voltage, for example, obtained from the sample voltage. This will give us the information that the measured voltage is greater or less. In many systems – for example regulators is sufficient information. In systems where the large precision is required, compare measured voltage to mid-voltage of the sample, one fourth, one eighth and so on.
To create independent of the voltage level of the reference voltage, you need a special layout, i.e., the master voltage. This kind of elements are widely used in analog electronics and systems, mixed analog-digital devices such as regulators, controllers and converters analog-to-digital and digital-to-analog. These systems use a reference voltage to operate, in comparison with other voltages or voltage conversion, the specified analog signal in digital form.
It is necessary to distinguish models of voltage from normal voltage regulators (linear and switching), if they behave similarly. Leave certain voltage regardless of supply voltage. However, there are a number of features. The voltage standards are much more accurate and stable, and has a lower output current, which allows the voltage reference of such a layout should be cached, for example, using an operational amplifier.
There are many methods (physical phenomena), used in the construction of the samples of the voltage. The first reference voltage was electrochemical processes, however, such devices are very impractical and cannot be used outside the laboratory. The next generation of systems for stabilization of the reference voltage was based on the sparkling lamps. The introduction of semiconductor chips was the next step in the development of standards tension. The first was the Zener diode, and is currently most commonly used system based on the amount of the voltage drop across the diode ssd and the difference of the voltages at the two connections PN different values of the flowing current. This solution provides high temperature stability, to focus on the fact that the effects used are, respectively, negative and positive temperature coefficient, wypadkowo compensating each other.
The typical application of tension help systems are mixed, i.e., analog-to-digital, which use voltage levels in the system responsible for value conversion analog to digital. In the digital domain all the amplitude values from the fact dimensionless. Only at the moment of translation from and into analog value, are converted at a fraction of the full scale voltage of the corresponding circuit. Often this voltage is pochodzącemu voltage from the sample voltage.