The invention relates to the technical field of circuits, and discloses a power supply soft start circuit and a
switching power supply suitable for
new energy and
electric power products, which are suitable for flow batteries, photovoltaic inverters, intelligent
direct current metering and
control equipment, light stacking controllers and the like, and control
chip output and realize soft start by controlling a feedback pin of a
chip. Parameters can be set by adjusting external resistors and capacitors, surge can be suppressed, output
capacitor charging current is prevented from reaching a limit at the starting moment of a power supply, current stress and input
voltage drop to the circuit and the rear end are reduced, and a power-on
time sequence can be controlled. The method does not need to pay for the unused soft start function in the
chip, only needs to replace the unit elements when damaged, is low in cost, and is suitable for low-power or cost-sensitive scenes. And high-temperature-resistant and high-pressure-resistant discrete components can be used for improving the reliability, and low-cost discrete components can also be used. The circuit is wide in applicability, can adjust the
delay time, and is adaptive to each chip. The structure is simple, external devices are few, and cost is low.