R
Randall Nortman
- Jan 1, 1970
- 0
I have to admit to being a bit ignorant about the various types of
capacitors available, for example NPO, X7R, etc. I believe these
abbreviations refer to the type of dielectric used, which influences
the properties of the capacitor. Can anybody point me to a key for
deciphering these codes, preferrably with some information on what the
relevant properties of the different types are?
And what is the best type of capacitor/dielectric for basic power
supply decoupling/bypassing on digital logic ICs (e.g.,
microcontrollers) with clock speeds up to about 50MHz. I have often
seen datasheets recommend two different types of capacitor in parallel
-- is this to eliminate harmonics that would be present with only one
type? If I have a single big 47uF capacitor between the Vcc and
ground planes somewhere on the board, and one 0.1uF capacitor at every
Vcc pin, does this solve the problem? What dielectric types or other
specs should each of those have?
I'm specifically looking for surface-mount chip-type capacitors, if
that matters. (I suppose the 47uF should be a can-style through-hole
capacitor, presumably electrolytic?)
Thanks for any advice,
capacitors available, for example NPO, X7R, etc. I believe these
abbreviations refer to the type of dielectric used, which influences
the properties of the capacitor. Can anybody point me to a key for
deciphering these codes, preferrably with some information on what the
relevant properties of the different types are?
And what is the best type of capacitor/dielectric for basic power
supply decoupling/bypassing on digital logic ICs (e.g.,
microcontrollers) with clock speeds up to about 50MHz. I have often
seen datasheets recommend two different types of capacitor in parallel
-- is this to eliminate harmonics that would be present with only one
type? If I have a single big 47uF capacitor between the Vcc and
ground planes somewhere on the board, and one 0.1uF capacitor at every
Vcc pin, does this solve the problem? What dielectric types or other
specs should each of those have?
I'm specifically looking for surface-mount chip-type capacitors, if
that matters. (I suppose the 47uF should be a can-style through-hole
capacitor, presumably electrolytic?)
Thanks for any advice,