Low-dropout linear regulator works

Crystal oscillator

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

TP-IP4220CZ6 5V 0.35PF breakdown voltage 6V SOT

Shunuo varistor / ESD varistor / product complete / Sunlord first-class agent

Crystal resonator 2.5*2.0mm 2520 16MHZ (16.000MH

As shown in the figure to the right, the circuit consists of a series adjustment tube VT, sampling resistors R1 and R2, and a comparison amplifier A.

The sampling voltage is applied to the non-inverting input terminal of the comparator A, and compared with the reference voltage Uref applied to the inverting input terminal, the difference between the two is amplified by the amplifier A, and the voltage drop of the series regulating tube is controlled to stabilize the output voltage. When the output voltage Uout decreases, the difference between the reference voltage and the sampling voltage increases, the drive current of the comparison amplifier output increases, and the series regulator tube voltage drop decreases, thereby increasing the output voltage. Conversely, if the output voltage Uout exceeds the desired set value, the pre-drive current of the comparator output is reduced, thereby reducing the output voltage. During the power supply process, the output voltage correction is continuously performed, and the adjustment time is limited only by the reaction speed of the comparison amplifier and the output transistor loop.

It should be noted that the actual linear regulator should also have many other functions, such as load short circuit protection, over voltage shutdown, thermal shutdown, reverse connection protection, etc., and the series regulator can also use MOSFET.