DC-DC Converter Working Principle
The DC-DC converter is a voltage converter that effectively outputs a fixed voltage after converting the input voltage. DC to DC converters are divided into step up DC-DC converters, step down DC- DC converters, and buck-boost DC-DC converters. Three types of controls can be used according to requirements. At present, DC to DC converters are widely used in products such as mobile phones, MP3s, digital cameras, and portable media players. The circuit of DC converter belongs to the chopper circuit in the circuit type classification.
DC to DC converter working principle
DC to DC means DC to DC conversion. There are three types DC converter on ATO.com, including boost converter, buck converter and boost-buck converter. The output current of the step-down DC to DC converter is relatively large, mostly hundreds of milliamperes to several amperes, so it is suitable for occasions with relatively large output current. The basic working principle circuit of the step down converter is shown in the figure 1 below. VT1 is a switch tube. When VT1 is turned on, the input voltage Vi supplies power to the load RL through the inductor L1, and at the same time it also charges the capacitor C2. In this process, energy is stored in the capacitor C2 and the inductor L1. When VT1 is off, the energy stored in the inductor L1 continues to supply power to RL. When the output voltage is going to drop, the energy in the capacitor C2 is also discharged to RL, maintaining the output voltage unchanged. The diode VD1 is a freewheeling diode to form a circuit loop. The output voltage Vo is divided by the voltage divider composed of R1 and R2, and the signal of the output voltage is fed back to the control circuit. The control circuit controls the on and off time of the switch tube to keep the output voltage unchanged.
Figure 1: Basic Working Principle Diagram of DC to DC Converter
To design DC-DC circuit should consider the following conditions:
- The range of the external input power supply voltage and the size of the output current.
- The maximum value of DC-DC output voltage, current, and system power.
In short, the DC to DC converter supplies power to each circuit in the entire system. Only by knowing the DC to DC converter circuit design and its working principle can the overall performance of the system be improved.