Capacitor types
Types of Capacitors
(in descending order of stability)
- NP0 (negative positive zero, aka 'C0G', aka 'NPO')
- extremely stable in rf oscillators
- temperature stable
- crystal oscillators
- variable frequency oscillators (VFO)
- beat frequency oscillators (BFO)
- rf coupling circuits
- temperature use -55C to 125C
- capacitance change +/- 0 to 30ppm/C
- (silver) mica
- stable over wide temperature range
- rarely fail
- often used for oscillators
- same use as NP0 (RF circuits)
- capacitance change +/- 0 to 50ppm/C
- polystyrene (film)
- good for oscillators
- stable but keep in cool temperatures
- capacitance changes permanently when heated too much
- used in solid state equipment (around tubes is too hot)
- ceramic
- rarely fail
- rf bypass capacitors
- never use for oscillators or tuned circuits
- slightly microphonic
- X5R (-55C to 85C)
- X7R (-55C to 125C)
- Y5V (-30C to 85C)
- Z5V (10C to 85C)
- PP/polypropylene (film) (orange/brown/green drop)
- rf coupling
- good for audio amps
- not for oscillators
- not very stable
- PET/polyester (film) (MKT, Mylar)
- heat and humidity resistance
- tantalum
- not for audio
- non-linear
- good for rf bypass
- good for timing (e.g. 555)
- available in capacitances well above 1uF
- polar
- temperature stable
- Electrolytic (aluminium film)
- poor stability
- available in capacitances well above 1uF
- good for timing (e.g. 555)
- polar
- paper in oil
- stability ok
- replace (paper goes acidic over time)
- replace with polypropylene
- foil capacitor (old style)
- stability ok
- replace with polypropylene