Self-adaptive filtering control circuit applied to multi-voltage output LDO chip

Abstract

The invention discloses a self-adaptive filtering control circuit applied to a multi-voltage output LDO chip, and belongs to the field of integrated circuit design. The self-adaptive filtering controlcircuit comprises an error amplifier, a buffer circuit, a resistance feedback network, a control circuit and a self-adaptive filtering circuit; the error amplifier and the buffer circuit are used forgenerating and amplifying a negative feedback signal; the resistance feedback network is used for controlling the output voltage; the control circuit is used for generating a control voltage; and theself-adaptive filtering circuit is used for filtering power supply voltage noise. When the control signal generated by the control circuit is used for controlling a MOS switch, filtering is carried out by the self-adaptive filtering circuit, so that the PSRR index of the LDO is prevented from being influenced by power supply noise. The self-adaptive filtering control circuit has the following technical advantages that firstly, the structure of the self-adaptive filtering control circuit not only can reserve the advantages of a traditional resistance feedback network, but also can avoid the existing problems; and secondly, a large resistor required by the filtering circuit can be integrated in a low-cost on-chip manner and is self-adaptive, so that the possibility that the circuit is cut off due to overlarge resistance can be prevented.

Description

technical field [0001] The invention relates to the field of integrated circuit design, in particular to an adaptive filter control circuit applied to a multi-voltage output LDO chip. Background technique [0002] In the field of integrated circuit design, LDO (Low Dropout Linear Regulator) chips have drawn extensive attention from the industry because of their importance. LDO is used to provide clean and stable power to other chip modules in the circuit system. In order to realize the low-noise performance of the chip, people put forward high requirements on the PSRR (power supply rejection ratio) of the LDO. At the same time, with the development of technology, the types of chips have become extremely rich, and the power supply voltage that needs to be provided by the LDO is also very large. In order to reduce the design cost, it is generally necessary to design the LDO into a multi-voltage output mode, so the high PSRR LDO chip It has become a hot spot for design challe...

AI Technical Summary

Problems solved by technology

[0008] In order to overcome the problem that the resistance trimming network design adopted by the existing LDO technology is difficult to solve the problem that the multi-voltage output is directly affected by the power supply noise, the present invention provides an adaptive filter control circuit applied to the multi-voltage output LDO chip

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