Low drop-out linear voltage stabilizing circuit having function of high-frequency transient voltage protection

Abstract

The invention relates to a low drop-out linear voltage stabilizing circuit having the function of high-frequency transient voltage protection. A pair of parallel low-pass filters, a transient high-voltage clamping circuit and a low drop-out linear stabilizer function as current regulators and are utilized for providing well-regulated constant current to an electric load, such as a motor and an LED. The pair of low-pass filters comprises a main input filtering capacitor and a damping resistance capacitor.A high-frequency effective transient voltage clamping circuit is composed of triodes and a collection diode and used for controlling the triodes connected in series. The high-frequency clamping effect is similar to a voltage regulator such that input and output of the pair of low-pass filters are coupled for receiving a filtered input signal. In the meantime, output of the voltage regulator and output of the low drop-out linear stabilizer are coupled. The low drop-out linear voltage stabilizing circuit having the function of high-frequency transient voltage protection has following beneficial effects: due to the fact that the transient high-voltage clamping circuit comprises a battery supply having an overvoltage condition in absence of a clamping function and a voltage clamping circuit is used for clamping extra powder on overvoltage condition, the low drop-out linear stabilizer is protected.

Description

technical field [0001] The invention relates to the field of driving circuits for LED lamps of automobiles, in particular to a low-dropout linear voltage stabilizing circuit based on constant current regulation and high-frequency transient voltage protection. Background technique [0002] LED lighting technology has been applied in various electronic fields, such as architectural lighting, automobile head and tail lights, backlight of LCD liquid crystal screen and so on. LEDs offer significant advantages over traditional light sources such as incandescent and fluorescent lamps, including high efficiency, good directional and color stability, high reliability, longer service life, small size, and environmental safety. [0003] LED is a device driven by current, so adjusting the current flowing through LED is an important control technology. Low dropout linear regulators in the form of integrated circuits are widely used to regulate voltage or current. A low dropout linear r...

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Problems solved by technology

[0004] At the same time, all electronic devices on the car, such as the instrument panel, center console, interior lights, exterior lights, etc., are connected to the same power line, and this power supply is a battery or an alternator, and their output The voltage is not stable

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