Low dropout linear voltage regulator (LDO) without off-chip capacitor for improving transient response and increasing power supply rejection ratio (PSRR)

Abstract

The invention relates to a low dropout linear voltage regulator (LDO) without an off-chip capacitor for improving transient response and increasing power supply rejection ratio (PSRR). The LDO without the off-chip capacitor comprises an error amplifier, a reference voltage source module, a power adjusting tube, an NMC Miller's compensating circuit, a PSRR enhanced network and a transient response intensifier circuit. According to the LDO without the off-chip capacitor, the NMC compensation technique is used for meeting the system stability requirement; a second-stage gm improved circuit of the amplifier is used for increasing the charging and discharging currents to the grid of the power tube; a slew rate intensifier circuit is introduced, needed currents can be provided for a load when the load of the LDO is subjected to step hopping from small to large, and thus the transient response capacity of the LDO is improved under the double actions. In addition, the PSRR enhanced network is additionally arranged to be used for controlling the PSRR feedback factors beta of the system, an original zero point is pushed to the position with higher frequency, and therefore the PSRR characteristic of the system is improved. The LDO without the off-chip capacitor is improved on the aspect of transient response and the aspect of PSRR.

Description

technical field [0001] The invention belongs to the technical field of power supply management, and in particular relates to a low-dropout linear voltage regulator chip without an off-chip capacitor that improves transient response and power supply rejection ratio. Background technique [0002] In the process of the development of high-tech electronics industry, power management chips play an extremely important role, which can provide stable voltage for the rest of the system. The abbreviation of the low-dropout linear voltage regulator chip is LDO (LowDropoutLinearVoltageRegulator), which belongs to the power management chip. Notable advantages are: simple structure, fast response, low output noise, and high integration. Popular in portable electronic devices, such as notebook computers, vehicle electronic accessories, mobile phones, MP3 and so on. The difference between an LDO with an off-chip capacitor and an LDO without an off-chip capacitor is whether the output of t...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the shortcomings of the above-mentioned existing non-external capacitor LDO's poor transient response and power supply rejection ratio, the present invention proposes a non-external capacitor LDO that improves the transient response and power supply rejection ratio

Images