DC-DC Converter

Time : Feb 06 2015Source :analogtechnologies Author : Analog Click :
    DC-DC converter is a voltage converter that changes input voltageinto output fixed voltage. The DC-DC converter can be divided into three categories: step-up DC-DC converter   step-down DC-DC converter and step-up and step-down converter. According to the demand, there are three types of control to choose:PWM with high efficiency has good output voltage ripple and noise; even after long time use, PFM has the advantages of small power consumption, especially when the load is small; PWM/PFM can achieve the control of small load and heavy load.At present, DC-DC converters are widely used in mobile phone, MP3, digital cameras, portable media players and other products.The following introduce is about the principle of DC-DC and design skills.


    What is DC (Direct current)? It indicates the DC power supply, such asdry batteries or vehicle batteries. The 100V power supply of household is AC power supply. If a converter can convert DC voltage (3.0V) into DC voltage(1.5V or 5.0V), we will call it switch power supply or switch regulator. Generally speaking, DC-DC converter is composed of a control chip, inductance coil, a diode, a triode and a capacitor.In the discussion of the performance of DC-DC converter, if a single control chip is considered, it is difficult to judge its advantages and disadvantages. We need to carry on the comprehensive judgment.

    When we design the DC-DC circuit, we must consider the following conditions:external input range of supply voltage, the size of output current, DC-DC output voltage, and system power maximum.