Power amplifier control system and method based on automatic level control

Abstract

The invention discloses a power amplifier control system and a method based on automatic level control. The device mainly comprises a controllable attenuation circuit and the like. A first input end of the controllable attenuation circuit is connected with signal input, a second input end of the controllable attenuation circuit is connected with an output control signal Vp of a differential integrating circuit, an output end of the controllable attenuation circuit is connected with an input end of a signal transmission circuit, an output end of the signal transmission circuit is connected withan input end of the final-stage power amplifier tube, and an output end of the final-stage power amplifier tube is signal output; a temperature detection circuit is used for detecting the temperatureof the power amplifier. A voltage control circuit can be added to reduce the static power consumption of the power amplifier tube. The power amplifier has the beneficial effects that the power consumption is reduced by adopting a method of reducing the static power consumption of the power amplifier tube besides a method of reducing the power, and finally, the minimum output power and the power amplifier power consumption under the minimum static state are very small, so that the power amplifier can keep certain power output under an extreme high-temperature condition, and the system keeps apart of communication functions.

Description

technical field [0001] The invention relates to the field of power amplifier systems, in particular to a power amplifier control system and method based on automatic level control. Background technique [0002] Power amplifiers are widely used in electronic products such as communications and home appliances. They are mainly used to amplify high-power signals, increase signal strength, and improve signal coverage. With market demand and technological progress, the size of various electronic products is increasing. The smaller the power amplifier, the more complex the heat dissipation environment of the power amplifier will be, and the performance of the equipment will be seriously degraded or even damaged due to the high temperature of the equipment. [0003] The protection measures for the power amplifier of the existing products are usually when the temperature of the power amplifier module is detected to be higher than the preset threshold temperature, the power amplifier...

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Problems solved by technology

[0004] 1. The power reduction operation has a step limit. If the preset power reduction ratio is too large, the temperature of the power amplifier may be much lower than the threshold temperature but the power drop is too large, which greatly wastes the performance of the power amplifier; if the preset power reduction ratio If the ratio is too small, the power may drop too slowly, and the power amplifier cannot be protected in time;

[0005] 2. It is necessary to set an appropriate time interval during the power reduction operation, because there is a certain time process from reducing the power of the power amplifier to the detection of the temperature drop of the power amplifier. If the time interval is not set or the time interval is too short, the last power reduction Before the effect is reflected, it will enter the next power reduction operation, which will cause the output power of the power amplifier to decrease quickly or even perform the operation of turning off the power amplifier; but once this time interval is set, the power will definitely work when the temperature exceeds the threshold;

[0006] 3. The method of cooling is single, and only consider cooling down by reducing power and power consumption. In fact, when the output power of the power amplifier is reduced to a certain level, the power consumption reduction that the power reduction can bring is very small, even if the power amplifier has no output power. However, due to the existence of the quiescent working current of the power amplifier itself, it still has a large power consumption, so when the number of power reduction operations reaches the preset value, the power amplifier can only be completely turned off;

[0007] 4. For the purpose of protecting the power amplifier, if the temperature of the power amplifier still exceeds the threshold temperature after the number of power reduction operations exceeds the preset number of times, the operation of turning off the power amplifier will generally be adopted, and the power amplifier will not be turned on again after it is turned off; although this operation protects the power amplifier It is not damaged, but it will also cause the power amplifier function to fail completely, and the communication will be completely interrupted

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