Linear voltage regulator and power supply device

Abstract

The application discloses a linear voltage stabilizer and a power supply device. The linear voltage stabilizer comprises a power tube, an error amplifier, a current limiting circuit and a reference establishing circuit. The power tube has a current conduction path coupled between an input voltage and an output voltage and a control end receiving a gate drive signal. The error amplifier is used for comparing a feedback voltage with a first reference voltage and generating the gate drive signal according to a comparison result. The current limiting circuit is used for limiting the output current of the power tube to a current limiting value by pulling down the first reference voltage when a sampling current of the output current of the power tube is greater than the current limiting value. The reference establishing circuit is used for slowly rising the first reference voltage by charging a capacitor with a second reference voltage after current limiting is over. The linear voltage stabilizer can limit the output current of the LDO to a certain range when a system load is short-circuited, and can make the output voltage slowly and smoothly recover after current limiting is over, thereby avoiding overshoot of the output voltage.