A power conversion device

Abstract

The invention discloses an adaptive power supply circuit. Power is directly extracted from DC high voltage after the mains supply is rectified and filtered through a rectifying bridge and a filteringcircuit, and stable DC low voltage is generated for providing power for a system control circuit. The adaptive power supply circuit is characterized by comprising a high voltage isolation unit, a voltage adjusting unit, a feedback sampling unit, a reference voltage generation unit, and an error amplifying unit, wherein the high voltage isolation unit is used for isolating DC high voltage fluctuation caused by mains supply fluctuation to output first stable DC voltage; the voltage adjusting unit, together with the error amplifying unit and the feedback sampling unit, forms a negative feedback control loop for stabilizing second DC voltage outputted by the voltage adjusting unit; the feedback sampling unit carries out proportional sampling on the second DC voltage outputted by the voltage adjusting unit to output feedback voltage; the reference voltage generation unit outputs stable reference voltage; and the error amplifying unit carries out error amplifying on the reference voltage outputted by the reference voltage generation unit and the feedback voltage outputted by the feedback sampling unit to generate error amplifying signals, and thus, the second DC voltage outputted by thevoltage adjusting unit is proportional to the reference voltage.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to a power conversion device directly connected to the mains. Background technique [0002] With the rapid development of power semiconductor technology, power conversion devices, especially power conversion devices directly connected to the mains, are rapidly popularized. The power conversion device directly converts the power of the commercial power into a constant voltage or a constant current to supply a constant voltage load, or a constant current load similar to an LED. [0003] refer to figure 1 , Schematic diagram of the existing power conversion device architecture. The power supply circuit 13, the external resistor 14 and the external capacitor 15 cooperate with each other to directly rectify the mains 10 through the rectifier bridge 11, and the DC high voltage Vdc filtered by the filter circuit 12 is converted into a DC low voltage Vcc to supply power to the...

AI Technical Summary

Problems solved by technology

This will inevitably lead to the negative feedback loop having to discharge the excess current to GND through the MOS transistor 134 when the mains 10 is at a maximum value of 265Vac, resulting in a decrease in power supply efficiency, energy waste, and an increase in heat generation

[0005] At the same time, in order to maintain the low-voltage stability of the Vcc voltage, the existing power supply circuit has to isolate the high-voltage Vdc through the resistor R0 of the discrete device; but when the system control circuit 16 draws a large current instantaneously, the resistor R0 cannot provide enough energy, resulting in A power supply circuit must have a large discrete device energy storage capacitor 15 to maintain the instantaneous current drawn by the system control circuit 16, and the discrete device energy storage capacitor also leads to an increase in cost

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