Vehicle-mounted microcontroller, low-dropout linear regulator and overcurrent protection circuit of low-dropout linear regulator

Abstract

The invention provides a vehicle-mounted microcontroller, a low dropout regulator and an overcurrent protection circuit of the low dropout regulator. A comparison adjustment unit in the circuit is connected with a sampling unit and a voltage generation unit; the sampling unit is used for sampling breakover current of an adjusting tube in the low dropout linear regulator, converting the sampled breakover current into sampling voltage and outputting the sampling voltage to the comparison adjusting unit; the voltage generation unit is used for generating a comparison reference voltage according to a preset bias voltage and outputting the comparison reference voltage to the comparison adjustment unit; the comparison adjusting unit is used for comparing the sampling voltage with comparison reference voltage and performing feedback control on the grid voltage of the adjusting tube when the sampling voltage and the comparison reference voltage represent overcurrent of the adjusting tube, so as to realize overcurrent protection on the adjusting tube and solve the problem that the output current of the low-dropout linear voltage regulator is too large and the over-current of the low-dropout linear voltage regulator is too high. And the circuit of the low-dropout linear voltage regulator is not functional, so that the reliability of the circuit of the low-dropout linear voltage regulator is improved.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to a vehicle-mounted microcontroller, a low-dropout linear voltage regulator and an overcurrent protection circuit thereof. Background technique [0002] In the development of integrated circuit power management, low-dropout linear regulators are widely used in power systems because of their stable output voltage, small footprint, low noise, and fewer external devices. [0003] like figure 1 As shown, the conduction current of the adjustment tube MP1 in the low-dropout linear regulator is sampled by the sampling unit, and the sampling current is converted into a sampling voltage and then connected to the inverting input terminal of the error amplifier A1, which is connected to the reference voltage connected to the non-inverting input terminal. VREF is compared, and the difference between the two is amplified by the error amplifier A1 to control the on-current of the re...

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Problems solved by technology

[0005] In this regard, the application provides a vehicle-mounted microcontroller, a low-dropout linear voltage regulator and an overcurrent protection circuit to solve the problem that the output current of the low-dropout linear voltage regulator is too large, which will cause excessive power consumption and damage to the adjustment tube, and Issues that cause circuits of low dropout linear regulators to lose function and improve the reliability of low dropout linear regulator circuits

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