Device for improving power supply load regulation rate

Abstract

The invention discloses a device for improving the power load regulation. The device comprises an adjustable reference voltage source, an output current sampling compensation module, an output compensation signal filtering module, an output voltage sampling feedback module and a resistance arranged on an output line, wherein the adjustable reference voltage source is connected with a positive direction input end of a voltage error amplifier and used to adjust the output voltage by adjusting the reference voltage of the positive direction input end of the voltage error amplifier; the output current sampling compensation module is used to sample the output current and process sampled signals into compensation signals which are transmitted to the output voltage sampling feedback module; the output compensation signal filtering module is used to filter the compensation signals outputted by the output current sampling compensation module and output the filtered compensation signals to the voltage sampling feedback module; the output voltage sampling feedback module is connected with a negative direction input end of the voltage error amplifier used to real-time monitor the output voltage.

Description

technical field [0001] The invention relates to the communication field, and more particularly relates to a device for improving the load regulation rate of a power supply. Background technique [0002] The power supply for communication usually forms a system of various capacities to supply power to the load. Different loads have different requirements for the load regulation rate of the power supply. The industry standard of "High Frequency Switching Rectifier for Communication" requires the load regulation rate to be no more than 0.5%, but there are The equipment has higher requirements on the adjustment rate of the power supply. In the early power supplies, when the output current exceeds 50A, the output terminal usually uses a bus bar to reduce the output resistance and voltage drop, and the load regulation rate can easily meet the industry requirements; however, as the volume of the power supply continues to shrink and the power density continues to increase, the outpu...

AI Technical Summary

Problems solved by technology

[0006] Second, if the output voltage is changed by adjusting the output voltage sampling resistor, the load regulation rate of the power supply after changing the output voltage will change accordingly, which cannot guarantee ideal compensation within the full range of output voltage changes. For example, after output setting voltage compensation If the adjustment rate is theoretically zero, overcompensation will occur after the output voltage is increased, that is, the larger the output current, the higher the output voltage will be, and the compensation will be insufficient after the output voltage is lowered.

[0007] Third, in order to achieve effective compensation for certain output line resistors R3, R4 and VERF, sometimes there are strict requirements on the compensation resistors, making it difficult to select the type, and it is difficult to directly use the existing output current sampling shunt

In the communication power supply that outputs large current, a shunt of several milliohms or a few tenths of milliohms (with an accuracy of ±1%) is generally used as the sampling resistor of the output current. Small, such as VREF=2.5V, R3+R4=5mΩ, output 53.5V, then the output compensation resistor R5 should be 0.245mΩ±1% when the load regulation rate is zero, and the sampling shunt used to improve the load regulation rate must be less than Only 0.245mΩ can be used. You can’t directly borrow the existing shunt at the output terminal for output current sampling, but the resistance value exceeds the resistance value required to compensate the load adjustment rate to zero; the smaller the resistance, the smaller the power consumption, reducing useless loss. It is better to look at it, but the resistance is too small and the sampling signal is too small, the useful signal is easily disturbed by noise, resulting in a large detection error, it is difficult to achieve the expected effect of various effective controls after the output current is sampled, and the second is in the production of the shunt itself And during the assembly and welding process of the shunt on the PCB, its accuracy is difficult to control, and it will also bring too many defective products

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