What is a voltage reference device?
What is a voltage reference device?
Voltage references are electronic components, devices or circuits that are designed to deliver a constant DC (direct current) output voltage – in other words, a fixed voltage – irrespective of inconsistencies in other external conditions.
What do we use as a standard for voltage reference?
Zener diodes are also frequently used to provide a reference voltage of moderate stability and accuracy, useful for many electronic devices. The most common voltage reference circuit used in integrated circuits is the bandgap voltage reference.
What is voltage reference source?
A voltage reference is an accurate, temperature-compensated voltage source that provides specific output voltage values, such as 1.225 V, 4.096 V, or 10.000 V. Voltage reference ICs can be either shunt (two terminals) or series (three terminals).
What is analog voltage reference?
Analog-to-digital converters (ADCs) need a reference voltage (VREF) input in order to operate properly. ADCs convert analog inputs that can vary from zero volts on up to a maximum voltage level that is called the reference voltage. VREF is also related to the resolution of the ADC.
What is the difference between voltage regulator and voltage reference?
A voltage regulator is designed to take a variable voltage in (say, 2-5v), and output a constant voltage (say, 3.3v). On the flip side, a voltage reference is designed to take a variable voltage, and deliver EXACTLY the rated output voltage.
What is reference voltage in opamp?
Reduces an input voltage by the voltage divider fraction f=R2R1+R2 . Delivers an output with low output impedance: just the non-ideal Ro of the op-amp (or 0 if ideal).
What is a shunt voltage reference?
Shunt Reference It can be regarded as a voltage-controlled current source between the OUT and GND terminals. Regulation is achieved by adjusting the current level so that VSUPPLY minus the drop across R1 equals the reference voltage at OUT. The power supply delivers the same maximum current regardless of load.
What is voltage reference in voltage regulator?
Voltage references have much more precise and stable output, but cannot source or sink any significant amount of current. They’re typically used in precision analog circuitry, e.g. with ADCs. An example of a voltage reference is the TI REF02, which will output 5V ± 10 mV (0.2%), but can only source about 10 mA.
What is the voltage reference VREF in a voltage regulator Why is it needed?
Accurate measurements require a reference voltage that does not fluctuate with system conditions such as input voltage or ambient temperature. A voltage-reference IC provides a steady voltage that other ICs use to make measurements with the required accuracy.
Which is the 1% accurate voltage reference?
With a 1% accurate device at room temperature, the output voltage is 5.00V plus or minus 50 mV. If the current through the device varies from 1 mA to 15 mA, the voltage drop is guaranteed to change a maximum of an additional 10 mV. Figure 3 shows a typical circuit. FIGURE 3. 1% accurate, 5V reference.
How do you choose a voltage reference for a resistor?
The shared reference/resistor terminal is the output. The resistor must be chosen such that the minimum and maximum currents through the reference are within the specified range over the entire supply range and load current range. These references are quite easy to design with, provided the supply voltage and load current do not vary much.
When to use a voltage reference for calibration?
While the initial output voltage may vary from unit to unit, if it is constant for a given unit, then it can be easily calibrated. This specification is the most widely used to evaluate voltage reference performance, as it shows the change in output voltage over temperature.
How is temperature related to a voltage reference?
In contrast, the temperature drift of a reference specified as 5ppm/°C will be dominated by the nonlinearities. This can be easily seen in the output voltage vs temperature characteristic of Figure 2. Note that there are two possible temperature characteristics represented.