Varieties and characteristics of patch capacitors:
Monolithic ceramic capacitors (commonly known as patch capacitors) are commonly used components with large consumption at present, which have the potential to replace tantalum capacitors. There are different standards such as NPO (COG), X7R, X5R, Y5V and so on. NPO, X7R, X5R and Y5V are the temperature characteristic codes of capacitors, which are mainly caused by the different filling media of capacitors. The capacitors filled with different media have different capacity, dielectric loss, capacity stability and so on. .
Here we mainly introduce the temperature-compensated NPO (COG) capacitors:

NPO is one of the most commonly used monolithic ceramic capacitors with temperature compensation characteristics. Its filling medium is composed of rubidium, samarium and some other rare oxides. NPO capacitor is one of the most stable capacitors in capacitance and dielectric loss. The capacitance changes to 0 ±30ppm/ ℃ when the temperature is from-55 ℃ to + 125C, and the change of capacitance with frequency is less than ±0.3Δ C. The drift or lag of the NPO capacitor is less than ±0.05%, which is negligible compared to the thin film capacitor greater than ±2%. The change of typical capacity relative to service life is less than ±0.1%. The capacitance and dielectric loss of NPO capacitors vary with frequency with different packaging methods, and the frequency characteristic of large package scale is better than that of small package scale.

贴片电容的品种和特色:
    单片陶瓷电容器(通称贴片电容)是当前用量比较大的常用元件,有替代钽电容之势，有NPO(COG)、X7R、X5R、Y5V等不一样的标准, NPO、X7R、X5R和Y5V是电容的温度特性代号，主要因电容填充介质不一样而导致。不一样填充介质的电容器的容量、介质损耗、容量安稳性等也就不一样。 
    在这里我们主要介绍下温度抵偿型 NPO(COG) 电容器：
    NPO是一种常用的具有温度抵偿特性的单片陶瓷电容器。它的填充介质是由铷、钐和一些其它稀有氧化物构成的。NPO电容器是电容量和介质损耗安稳的电容器之一。在温度从-55℃到+125℃时容量改变为0±30ppm/℃,电容量随频率的改变小于±0.3ΔC。NPO电容的漂移或滞后小于±0.05%,相对大于±2%的薄膜电容来说是能够忽略不计的。其典型的容量相对运用寿命的改变小于±0.1%。NPO电容器随封装方式不一样其电容量和介质损耗随频率改变的特性也不一样,大封装尺度的要比小封装尺度的频率特性好。