Start-up surge current of DC-DC converter

surge power. This surge power can have adverse effects on the circuit, so measures need to be taken to suppress its occurrence. This article will introduce the causes and corresponding methods of surge power generated when the DC-DC converter is powered on.

The basic working principle of a DC-DC converter is to control the transfer of energy by switching switching tubes. When the switch is turned on, the energy from the input power supply is stored in the inductor; when the switch is turned off, the energy stored in the inductor is released to the output terminal, thereby adjusting the output voltage. In this process, the characteristics and working status of each component in the circuit will affect the stability of the output voltage, so it is necessary to have a deep understanding of the causes of surge power.

Also Read: Mainstream DC-DC Converter Types

DC-DC converters experience various surge powers for several reasons, which are mainly due to:

1. Transient overvoltage in the circuit: When a switch tube is turned on, the current in the inductor increases rapidly, which may cause transient overvoltage in the circuit. This overvoltage can adversely affect other components in the circuit and even cause component damage.
2. Leakage inductance and resistance losses of components such as inductors and capacitors: Components such as inductors and capacitors will inevitably produce leakage inductance and resistance losses during operation. These factors may cause additional voltage drops in the circuit, thus affecting to the stability of the output voltage.
3. The conduction angle of the switch tube and the transient failure of the trigger circuit: The conduction angle of the switch tube and the transient failure of the trigger circuit can also influence the generation of surge power. For instance, if a switch tube turns on in a non-ideal state, it may cause a large current spike. This current spike can create voltage fluctuations in the circuit, which can then impact the power supply.

To suppress the generation of surge power, several measures can be taken:

1. Filtering measures: The impact of transient overvoltage or other irregular signals can be reduced by adding filters or other suppression components to the circuit. For example, an appropriate resistor and capacitor can be added to the circuit to form an RC filter that reduces transient overvoltage.
2. Component matching: Selecting and matching components such as inductors or capacitors合理 can reduce voltage drops and resistive losses in the circuit, thereby minimizing the generation of surge power.
3. Adjusting the conduction angle of the switch tube: By optimizing the conduction angle of the switch tube, the current peak when the switch tube is turned on can be reduced, thereby minimizing the generation of surge power. For example, adjusting the delay time of the trigger circuit can control the conduction angle of the switching tube.
4. Component selection and layout optimization: Selecting components with low leakage inductance and low resistance while optimizing the circuit board layout to reduce line impedance can also effectively suppress the generation of power surges.

In practical applications, appropriate measures are selected based on specific cases. For example, in a high-power DC-DC converter, it was found that the output voltage produced a large surge voltage at the moment the power was turned on. By adopting the filtering measures mentioned above, component matching, and inductors and capacitors among other components, the output voltage fluctuation has been successfully reduced, and the problem of impact power supply has been resolved.

In general, it is very important to understand the causes of power surges when the DC-DC converter is powered on and the corresponding solutions. By optimizing the design of the circuit, selecting high-quality components and rational layout, the generation of impact power can be effectively reduced and the stability and reliability of the DC-DC converter can be improved. As the application field of DC-DC converters continues to develop, we believe that more innovative solutions will appear in solving the problem of impact power supply in the future. Current Logic has been manufacturing the best DC-DC Convertors.