There are half-a-dozen ceramic dielectrics in regular use today: the ultra stable Class 1 types P90 (porcelain), NPO (COG)  and U2J (N2200), and the stable Class II types X7R, X5R and Y5V.

With increasing use of electronic modules in under-the-hood applications in the automotive industry, X8* type ceramic dielectrics are also becoming more and more popular.

X8G, X8L and X8R are all high temperature ceramic dielectrics for use in demanding applications up to +150°C, and all have a lower operating temperature limit of -55°C. This is what the “X” and the “8” signify. The third character represents the capacitance change over this temperature range. The table below shows this capacitance change.

Ceramic TypeRated Temperature RangeMaximum Capacitance Change Over Temperature Range
X8G-55°C - +150°C0±30ppm/°C
X8L-55°C - +150°C±15%
X8R-55°C - +150°C+15/-40%

 

This means that X8L and X8R types are stable Class II dielectrics, while the rarer X8G type is an ultra stable Class I dielectric.

The table below lists data sheets for all XRG, X8L and X8R capacitors in production today. 

Major brands such as AVX, KEMET, Knowles, Murata, TDK and Vishay all produce X8L/X8R dielectrics, but only Knowles and Murata have X8G types.