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Anyone have an MC34063 SPICE model lying around?

Started by Tim Wescott January 25, 2012
Title says it all.  LTSpice preferred.

While we're on the subject -- does anyone know what the error amplifier 
gain is in the MC34063, and what ranges one can expect in real life?  The 
data sheets all call it a "comparator", but reading between the lines 
it's a gain stage followed by a comparator to the oscillator (which is 
what it has to be, to work correctly).

-- 
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
"Tim Wescott" <tim@seemywebsite.com> wrote in message 
news:WNydnS20ir2wo73SnZ2dnUVZ_jWdnZ2d@web-ster.com...
> Title says it all. LTSpice preferred. > > While we're on the subject -- does anyone know what the error > amplifier > gain is in the MC34063, and what ranges one can expect in real life? > The > data sheets all call it a "comparator", but reading between the lines > it's a gain stage followed by a comparator to the oscillator (which is > what it has to be, to work correctly). > > -- > My liberal friends think I'm a conservative kook. > My conservative friends think I'm a liberal kook. > Why am I not happy that they have found common ground? > > Tim Wescott, Communications, Control, Circuits & Software > http://www.wescottdesign.com
onsemi has spice models for the MC34063 Cheers
I'd just as well dump it, it's old and the "current mode" control is
terrible -- it's even poorly defined just what it does (increase
frequency and decrease duty cycle).  Lots of monolithic solutions on
the market today -- actually, too many, it takes way too long to
select one from any distributor's parametric search or catalog.  I
forget the LT and ADI chips I've picked lately (obviously...I have the
numbers at work..), but they always seem to be available, and with
little wisdom required on my part, the datasheets are pretty good at
showing how to set it up (including compensation), at least LT's
(their documents are almost always very thorough and helpful, which
you see in their pricing..).

Tim


On Jan 25, 11:38=A0am, Tim Wescott <t...@seemywebsite.com> wrote:
> Title says it all. =A0LTSpice preferred. > > While we're on the subject -- does anyone know what the error amplifier > gain is in the MC34063, and what ranges one can expect in real life? =A0T=
he
> data sheets all call it a "comparator", but reading between the lines > it's a gain stage followed by a comparator to the oscillator (which is > what it has to be, to work correctly). > > -- > My liberal friends think I'm a conservative kook. > My conservative friends think I'm a liberal kook. > Why am I not happy that they have found common ground? > > Tim Wescott, Communications, Control, Circuits & Softwarehttp://www.wesco=
ttdesign.com
There's an MC34063 model in the LTSpice files of the yahoo group.

RL
On Wed, 25 Jan 2012 19:16:53 -0800 (PST), Tim Williams
<tmoranwms@gmail.com> wrote:

>I'd just as well dump it, it's old and the "current mode" control is >terrible
It is inefficient, and the LT model is not always covering the correct Ct frequency you actually get. ... but it is very cheap, and when tuned well, it does the job with modest RFI issues and LF whistles. They are used in millions in eg cigarette lighter 12 - 5V USB chargers. Hyper efficient MHz switchers may require more attention.