Self-adapting current multiplication circuit and low-dropout-voltage linear voltage regulator integrating same

Abstract

The invention discloses a self-adapting current multiplication circuit and a low-dropout-voltage linear voltage regulator integrating the circuit. Firstly, constant bias voltage of an NMOS transistor and constant bias voltage of a PMOS transistor are generated through a constant bias voltage generating circuit, and then a lagging current comparator collects small part of load current which is compared with constant current; when a load is in a light load, the lagging current comparator shuts off a self-adapting current multiplication generating circuit, self-adapting current multiplication voltage VBPA rises, the bias current of an operational amplifier of the low-dropout-voltage linear voltage regulator lowers, in this way, stability is guaranteed, and quiescent dissipation is reduced; when the load is in a heavy load from a moderate load, the lagging current comparator turns on the self-adapting current multiplication generating circuit, the self-adapting current multiplication voltage VBPA lowers, the bias current of the operational amplifier increases to the specific times the bias current of the operational amplifier during the light load, the gain bandwidth product of the low-dropout-voltage linear voltage regulator increases, and transient response performance is enhanced.

Description

technical field [0001] The invention belongs to the technical field of power supply management, and more specifically relates to an adaptive current multiplication circuit and a low-dropout linear voltage regulator integrating the circuit. Background technique [0002] Low dropout linear regulator is an important part of the power management system, it has the advantages of fast transient response, low quiescent current, simple structure, etc. It provides clean and stable energy for some noise-sensitive circuits, such as medical electronic circuits, etc. . [0003] Conventional low-dropout linear regulators require an off-chip filter capacitor with a capacitance of 0.1 to 10 μF at the output end. This capacitor makes the main pole of the low-dropout linear regulator at the output end to ensure the stability of the low-dropout linear regulator. At the same time Output voltage overshoot and undershoot during transient transitions are also absorbed. However, the existing tech...

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Problems solved by technology

However, the adaptive bias current technology is only effective when the low dropout linear regulator is heavily loaded. At medium load, the added bias current is very small, which hardly improves the performance of the low dropout linear regulator. At the same time, through The method of increasing the bias current by the gate voltage of the coupling regulator MP is significantly affected by the process and temperature, which reduces the robustness of the low dropout linear regulator

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