A low dropout linear regulator

Abstract

The embodiment of the invention discloses a low dropout regulator. An output end of a first power tube in the low dropout regulator is connected with an input end of a second power tube; a control end of the second power tube is connected with the output end of a mid-value voltage stabilizer; the input end of the mid-value voltage stabilizer is connected with an input power supply; the scope of an input voltage value of the input power supply is more than 0 but less than or equal to 2 times of the maximum working voltage of the first power tube or the second power tube; and a voltage value at the output end of the mid-value voltage stabilizer is a difference value of the input voltage value of the input power supply and the maximum working voltage of the first power tube or the second power tube. According to the technical scheme provided by the embodiment of the invention, the second power tube and the mid-value voltage stabilizer are additionally arranged, so that the scope of the working voltage of the low dropout regulator is effectively widened under the condition of only using the power tube with low threshold voltage, the low dropout regulator and the other circuits are more easily integrated onto a same chip, and thus the cost is greatly lowered.

Description

technical field [0001] Embodiments of the present invention relate to the field of electronic technology, in particular to a low-dropout linear voltage regulator. Background technique [0002] With the popularization of various portable electronic products, a power management IC (Integrated Circuit, integrated circuit) faces many challenges, and a DC voltage regulator chip plays a vital role. Low Drop Out Linear Voltage Regulator (LDO) has become the most popular DC voltage regulator chip because of its low power consumption, small size, stable output voltage, and small voltage ripple. [0003] figure 1 It is a circuit diagram of a low dropout regulator in the prior art. Such as figure 1 As shown, the low dropout linear regulator in the prior art includes an error amplifier A, a power transistor M P0 , the feedback resistor r 1 and the feedback resistor r 2 . The working principle of the low dropout linear regulator is as follows: The power supply V of the low dropout...

AI Technical Summary

Problems solved by technology

[0004] The low-dropout linear regulator in the prior art can achieve a stable output voltage, but the voltage range of its input power supply is relatively limited

If the voltage of the input power supply increases, the power transistor in the low dropout linear regulator will be broken down, so only a power transistor with a higher threshold voltage can be used, but the power transistor in the low dropout linear regulator will be in contact with the power supply The transistors used in other circuits of the management IC are different, and if they cannot be well integrated, a lot of space will be wasted, and the voltage range of the input power supply will conflict with the integration of the entire circuit.

At the same time, making a power transistor with a higher threshold voltage will require twice as many masks, making the entire process more complicated

Images