比较线性和开关稳压器低成本和稳定性等因素

　　了解线性稳压器的优缺点

　　设计者很清楚切换DC/DC变换器的效率，但线性调节器仍然是许多应用的最佳选择。理解原因将有助于确保设计者做出正确的选择并正确地执行它。

　　本文比较线性和开关稳压器，并显示如何简单，低成本和稳定性等因素也必须给予适当考虑，连同效率。

　　开关稳压器：高效但复杂

　　开关稳压器是高效的，能够升压（升压），降压（降压），并轻松地反转电压。现代模块芯片是紧凑，可靠，可从多个供应商。尽管有许多优点，开关调节器也有一些弱点（表1）。

　　Table 1： Comparison of the characteristics of switching and linear regulators. （Table source： Maxim Integrated）

　　First， they are complex chips， and consequently， it can take additional design effort to get a new product working properly. Second， the level of integration of contemporary switching regulators can be expensive， and also increases the chip size. Finally， all that high-frequency switching tends to be noisy.

　　Voltage and current ripple at the input and output filters generated by high-frequency operation can be a major issue for a design using a switching regulator. While these problems can be tackled， it takes time and design skill to do so.

　　Linear regulators address all the key weaknesses of the switching type. They are simple， low cost， require fewer external components， and there is no switching to generate excess noise. In the right application， these modest devices can be a good choice， as shown in Table 1.