Knowles brand, Dielectric Laboratories (DLI), has taken temperature performance to a level of 175°C in their Ultra-low ESR and High Q MLC capacitors.
DLI detailed the following:
“UL is an EIA Class I Stable TC, NP0, Ceramic dielectric, with Ultra Low ESR; High Q, and Low Noise. Parts can now be operated up to +175°C with TCC of 0 ± 60 ppm/ºC (limited to +125°C at 0 ± 30 ppm/°C). They find use in any application where heat generation or signal loss are concerns. They are considered High Voltage in that case size C07 and can be operated at up to 500Vdc over the capacitance range of 0.3pF to 47pF, extending to 100pF if de-rated to 200Vdc.
“The AH EIA Class I Positive TC, P90 Porcelain dielectric now achieves the +175°C rating with a TCC of 0 ± 20 ppm/ºC. Applications are where High Q, coupled with Low ESR, is a priority. They have a dielectric constant that increases with temperature (90ppm/°C) giving Established Reliability; Low Noise and High Self-resonance. Useful for temperature compensation where other board components may be losing capacitance with temperature. Capacitance range starts at 0.3pF and climbs to 1000pF over the voltage range 50V, to a high working voltage of 1kV.”