A low dropout linear regulator

Abstract

The invention provides a low dropout regulator. The low dropout regulator comprises an operational amplifier, an output switch pipe, a first resistor module and a second resistor module. The low dropout regulator further comprises a first switch pipe, a second switch pipe, a capacitor module and a third switch pipe, wherein a control end of the first switch pipe receives a preset clock signal, a first end of the first switch pipe is connected to a power source, a second end of the first switch pipe is connected to a power source end of the operational amplifier, the duty ratio of a low level to a high level in the preset clock signal is a:b, and b is larger than a and a is larger than zero; a control end of the second switch pipe receives the preset clock signal, a first end of the second switch pipe is connected to the output end of the operational amplifier, and a second end of the second switch pipe is connected to the control end of the output switch pipe; one end of the capacitor module is connected to the second end of the second switch pipe and the control end of the output switch pipe respectively, when the output switch pipe is a first NMOS pipe, the other end of the capacitor module is connected to the ground, and when the output switch pipe is a first PMOS pipe, the other end of the capacitor module is connected to a power source; a first end of the third switch pipe is connected to the second resistor module, a control end of the third switch pipe receives an inversion signal of the preset clock signal, and a second end of the third switch pipe is connected to the ground. The low dropout regulator is low in power dissipation.

Description

technical field [0001] The invention relates to the technical field of circuits, in particular to a low-dropout linear regulator. Background technique [0002] In modern society, more and more handheld electronic products have emerged, and most of these products are powered by batteries. As a power source, the output voltage of the battery is not constant during the use cycle, but gradually decreases with the use time. And the battery voltage is usually higher than the normal working voltage of the chip. For example, in some applications, the battery voltage is 3.6V, but the working voltage of the circuit in the chip is only 2.5V. In this case, a low-dropout linear regulator needs to be integrated in the chip to ensure that as long as the battery voltage is higher than 2.5V, the low-dropout linear regulator will output a stable 2.5V, so that the circuit can run safely and reliably. [0003] The existing low dropout linear regulator circuit such as figure 1 Shown: VCC' is ...

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Problems solved by technology

[0005] In view of the above problems, the purpose of the embodiments of the present invention is to provide a low-dropout linear regulator to solve the problem of large static power consumption of the existing low-dropout linear regulator

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