Ultra-low ESR & high Q MLC capacitors at high temps

February 15, 2016 // By Graham Prophet
Dielectric Laboratories (DLI, part of Knowles Capacitors), has announced a number of specification extensions to its ultra-low ESR and high Q MLC capacitors. In both cases DLI have taken the temperature performance to a higher level of 175C.

The improved TCC (temperature coefficient of capacitance) figures apply to DLI’s UL ceramic dielectric capacitors in case size C07 (0711) and AH porcelain dielectric capacitors in case size C17 (1111) – both with SMD compatibility. Applications range from impedance matching, power handling, dc blocking, bypass, coupling, tuning and feedback in circuit designs covering oscillators, timing, filters, rf power amplifiers and delay lines.

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 500 Vdc over the capacitance range of 0.3 pF to 47 pF, extending to 100 pF if de-rated to 200 Vdc.

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 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 0.3 pF and climbs to 1000 pF over the voltage range 50V, to a high working voltage of 1kV.

Knowles; www.knowlescapacitors.com