LDO multi-integrated protection circuit

Abstract

The invention discloses an LDO multi-integrated protection circuit. The LDO multi-integrated protection circuit connected with a basic LDO circuit comprises an input power VDD detection module, a temperature detection module, a current detection module and a protection module integrated and connected. The input power VDD detection module outputs a current Is1, the current detection module outputsa current Is2 corresponding to the basic LDO circuit, the temperature detection module outputs a current Iptc, output currents of the above three modules are connected to an adder, and the protectionmodule is connected among output currents of the detection modules, an input power supply VDD and a grating of a power tube Mp of the basic LDO circuit to realize current limiting protection for the basic LDO circuit. Design of a multi-integrated protection circuit is used, a PTC current generation circuit is introduced, current detection, temperature detection and input voltage detection are fused into integrated LDO protection, the current limiting performance of the LDO is improved reliably, and recovery time of self output IL is shortened.

Description

Technical field [0001] The invention relates to a protection circuit design of a low-dropout linear voltage stabilizer, in particular to a protection circuit integrating current limit, power limit and temperature monitoring for this type of voltage stabilizer. Background technique [0002] In the high-precision system design, not only the power supply is required to have high initial accuracy and high precision, but also the voltage is required to have a strong suppression effect on the medium and high frequency noise on the power supply. Especially in the fields of video surveillance and communication systems, the requirements for power supply voltage are more stringent. As a commonly used voltage conversion module, low-dropout linear regulators have very common applications in high-precision systems. The circuit composition includes a reference voltage Vref generating module, an error amplifier AMP, a power tube MP, and voltage divider resistors R1 and R2. The conventional wi...

AI Technical Summary

Problems solved by technology

The traditional temperature protection of this kind is independent, and it can only play a protective role when it reaches the over-temperature point, and this may cause the chip to burn out due to excessive power consumption before reaching the protection point when the temperature point setting deviation, or the temperature If the protection hysteresis is too small, if the temperature is not cooled in time, it will also lead to high power consumption and rapid temperature rise in an instant, causing the chip to burn out

[0004] On the other hand, the over-current protection is also independent, and the protection will not start until the preset current protection point is reached. During this period, overheating may occur without reaching the over-temperature point and burn the chip, especially the high-voltage input circuit, such as the highest power supply voltage. It is 40V, so the instantaneous power (P=V*I) will be very large, and it is easy to burn the chip

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