A standard linear regulator is also called NPN type linear regulator. The standard linear regulator is mainly composed of basic parts such as a reference voltage source, a sampling circuit, an error amplifier, and a regulator tube. It belongs to the traditional voltage stabilizer, which has the advantages of good voltage regulation performance, small output ripple voltage, simple circuit, and low cost.
The voltage regulator is used to provide a stable power supply voltage that does not change with load impedance, input voltage, temperature, and time. Low dropout regulators are known for their ability to maintain a small pressure difference between the supply voltage (input) and the load voltage (output).
A linear regulator is a type of integrated regulator that uses a transistor or FET operating in the linear region to subtract the excess voltage from the input voltage of the application to generate a regulated output voltage.
The function of the linear regulator is to provide a stable DC output voltage when the input voltage or load changes within the specified working range(three-phase voltage regulator: automatic voltage regulator), and to ensure that the voltage regulator circuit can work safely and reliably for a long time.
The feedback loop used to control the output voltage "judges" the output voltage through a sampling resistor and sends the sampled voltage to the non-inverting input of the error amplifier, and the reference circuit is connected to the inverting input.
The "linear" series regulator usually consists of a reference voltage source, a comparison link between the proportional output voltage and the reference voltage, a feedback amplifier, and a series regulator tube (bipolar transistor or FET tube). The amplifier is used to control the regulator. The voltage drop maintains the required output voltage value.
This means that the error amplifier will constantly adjust its output voltage and the current of the regulator tube to make the sampling voltage equal to the reference voltage. The output voltage of a linear regulator is usually several times the reference voltage.