Contents
How do I avoid inrush current?
Inrush current can be reduced by increasing the voltage rise time on the load capacitance and slowing down the rate at which the capacitors charge. Three different solutions to reduce inrush current are shown below: voltage regulators, discrete components, and integrated load switches.
How is inrush current of power supply calculated?
The peak value of the inrush current is determined by the equation, i=C*dv/dt. The capacitance is the total capacitance of the EMI filter and the input capacitance of the DC-DC converter. The dv/dt is the slope of the applied voltage waveform.
What is the purpose of boost converter?
The boost converter is used to “step-up” an input voltage to some higher level, required by a load. This unique capability is achieved by storing energy in an inductor and releasing it to the load at a higher voltage.
Why does my power switch have excessive inrush?
The demand for low output noise has pushed designers to implement heavy output filtering, such as using several capacitors at the output. With increased capacitance across the output rail, excessive inrush current may become an issue during startup that can potentially lead to inductor saturation or damage of the power switch.
How to prevent start up issues due to output inrush?
Due to its foldback nature and depending on the nature of the load, the operating point could fall into the foldback region toward the short circuit operating point once the current-limit threshold was reached or exceeded. This would require power cycling the part or re-enabling the part to get back to the normal operating condition.
Why does my switching converter not start up?
Switching converters on applications demanding reduced output noise may encounter delayed startup, or may not startup at all, due to excessive output inrush.
How does the reduction in output current ( IOUT ) work?
The reduction in output current (IOUT), as opposed to constant current-limiting, reduces power dissipation, thus reducing the thermal stress on the switching converter. Figure 3. V OUT vs. I OUT curve of constant and foldback schemes.