A Study Of Hybrid Capacitors Included Tantalum Capacitors Paralleled With Ceramic Capacitors

Capacitor is one of three fundamental components. In the circuits, it has been used for filtering, decoupling, bypassing and so on. A dramatic increasing in the frequency and packing density of integrated circuits required advancements in capacitors’ manufacturing technology. Nowadays, a wide variety of conventional capacitors have been available on the market today, and different capacitor has different electrical characteristics. For example, electrolytic capacitors, such as tantalum electrolytic capacitors, have been traditionally employed in applications where a high capacitance value were required. Multilayer ceramic capacitors(MLCCs)are typically quite effective for high frequency filtering applications. So in practical application, it is quite common that different types of capacitors have been used in a single integrated circuit, you can see that different types of capacitors maybe connected in parallel on a printed circuit board (PCB) as a discrete component. However, this also will bring the problem of the mutual influence of different types of capacitor’s parasitic parameters and it is not suitable for miniaturization.This paper focuses on an integrated hybrid capacitor which included chip tantalum capacitor and multilayer ceramic capacitor. At first, the paper introduces the difference of chip tantalum capacitor and multilayer ceramic capacitor included construction and electrical performance, then respectively illustrated their application areas. On the basis of this, constructing the structure of chip tantalum capacitor paralleled with multilayer ceramic capacitor. The hybrid capacitor can be moulded in a standard pad size and it is very convenient for using. On the electrical performance, the hybrid capacitor not only has the advantage of excellent frequency characteristic but also the large capacitance. It has very low equivalent series resistance (ESR).For a given capacitance, if increasing the equivalent series resistance, the power dissipation and ripple voltage of capacitor will be increased. What’s more, it can eliminate the piezoelectric noise of multilayer ceramic capacitor, which is one of the ceramic capacitor’s special features. The inherent nature of the ceramic material converts the mechanical vibrations to generally piezoelectric noise that will impact on circuit’s signal.In this paper, doing a lot of electric parameter tests and performance analysis of the chip tantalum capacitor, multilayer ceramic capacitor and the hybrid capacitor, including normal temperature electric parameters test, capacitance Versus the DC bias voltage characteristics, capacitance Versus frequency characteristic, the equivalent series resistance Versus frequency characteristic. Not only that, but also doing some environment tests and mechanical stress tests for paralleled hybrid capacitor, for example:temperature shock stability, high and low temperature stability, impact force stability, high firequency vibration stability. At last, the three kinds of capacitors proceed circuit simulation and actual filter circuit testing. Through tests and analysis, it can be seen that paralleled hybrid capacitor has good performance of electric parameters, stability, reliability and practical filtering results.