Interesting PFC Control IC (for PS gurus only)

  • Thread starter Harry Dellamano
  • Start date
H

Harry Dellamano

Guest
IRF has introduced the IR1150S control IC. It contains a proprietary "one
cycle control" for CCM PFC with no line voltage sense required. Pretty
neat!
But, can't we also use it in any DC/DC CCM loop, be it forward, flyback or
boost as a voltage feedforward control loop without actually looking at the
input voltage. Even better, will this controller not cure the dreaded
Harmonic Oscillation in peak current controlled CCM loops operated at >50%
duty?
OMG, I just wet my pants.
What say you, you power supply gurus?
Cheers,
Harry
 
Harry Dellamano wrote...
IRF has introduced the IR1150S control IC. It contains a proprietary
"one cycle control" for CCM PFC with no line voltage sense required.
Pretty neat!
But, can't we also use it in any DC/DC CCM loop, be it forward, flyback
or boost as a voltage feedforward control loop without actually looking
at the input voltage. Even better, will this controller not cure the
dreaded Harmonic Oscillation in peak current controlled CCM loops
operated at >50% duty? OMG, I just wet my pants.
What say you, you power supply gurus?
Cheers,
Harry
Click to expand...
http://www.irf.com/whats-new/nr050307.html
http://www.irf.com/product-info/datasheets/data/ir1150.pdf
http://www.irf.com/technical-info/refdesigns/irac1150-300w.pdf

"Pricing is US $1.05 each for the IR1150S/IR1150SPbF and
US $1.38 each for the IR1150IS/IR1150ISPbF..."

"The One Cycle Control method used in the IR1150 controller does not have
an analog multiplier, input voltage sensing, or fixed oscillator ramp,
simplifying circuitry and reducing component count. Instead, IR's OCC
uses a proprietary integrator with a reset circuit: The output of the
error amplifier is integrated over each clock cycle to generate a variable-
slope ramp. This variable ramp is compared with the error voltage and
subtracted from the current sense signal to generate the PWM gate drive."


--
Thanks,
- Win
 
Hello Harry,

IRF has introduced the IR1150S control IC. It contains a proprietary "one
cycle control" for CCM PFC with no line voltage sense required. Pretty
neat!
But, can't we also use it in any DC/DC CCM loop, be it forward, flyback or
boost as a voltage feedforward control loop without actually looking at the
input voltage. Even better, will this controller not cure the dreaded
Harmonic Oscillation in peak current controlled CCM loops operated at >50%
duty?
OMG, I just wet my pants.
What say you, you power supply gurus?
Click to expand...
Well, what does it cost? That is what it boils down to in the end. RHP
problems could be handled with regular chips, too. But even those were
too expensive in some of my designs so it ended up being all discrete or
logic chips.

Regards, Joerg

http://www.analogconsultants.com
 
Hello Winfield,

"Pricing is US $1.05 each for the IR1150S/IR1150SPbF and
US $1.38 each for the IR1150IS/IR1150ISPbF..."
Click to expand...
Thanks for the information. That is better than I thought, certainly a
good deal for large PFC circuits. Regular switchers, maybe not. I am
still holding out for something like the LM3478 but around 30 cents.

Regards, Joerg

http://www.analogconsultants.com
 
Joerg wrote...
Hello Winfield,

"Pricing is US $1.05 each for the IR1150S/IR1150SPbF and
US $1.38 each for the IR1150IS/IR1150ISPbF..."

Thanks for the information. That is better than I thought, certainly a
good deal for large PFC circuits. Regular switchers, maybe not. I am
still holding out for something like the LM3478 but around 30 cents.
Click to expand...
That level of pricing is only obtained with legacy parts produced at
paid-for yester-year backwater fabs. Not that there's anything wrong
with those parts or fab lines; we depend upon them for ICs, etc., for
lots of jelly-bean electronics products, such as PC power supplies.


--
Thanks,
- Win
 
Hello Winfield,

That level of pricing is only obtained with legacy parts produced at
paid-for yester-year backwater fabs. Not that there's anything wrong
with those parts or fab lines; we depend upon them for ICs, etc., for
lots of jelly-bean electronics products, such as PC power supplies.
Click to expand...
Maybe that's why my designs contain legacy parts almost exclusively.
Sometimes though I have the feeling that some mfgs want to front load
the amortization, trying to squish out whatever the market gives in the
first couple years. Not the IR1150S, that one seems fair in price.

Front loading can really hinder market entrance. I have looked at
several opportunities to swing a design to uC (MSP430). No chance, the
jelly bean concoctions beat it all the time. At least they need to come
out with a real bare bones version. It is amazing how cheap discrete SMT
designs are these days. And when, for example, a switcher or PFC can be
designed with CMOS logic then it's done that way.

Regards, Joerg

http://www.analogconsultants.com
 
Harry Dellamano wrote:
IRF has introduced the IR1150S control IC. It contains a proprietary "one
cycle control" for CCM PFC with no line voltage sense required. Pretty
neat!
But, can't we also use it in any DC/DC CCM loop, be it forward, flyback or
boost as a voltage feedforward control loop without actually looking at the
input voltage. Even better, will this controller not cure the dreaded
Harmonic Oscillation in peak current controlled CCM loops operated at >50%
duty?
OMG, I just wet my pants.
What say you, you power supply gurus?
Cheers,
Harry
Click to expand...
Keyue Smedley has written dozens of papers on one-cycle control; Dragan
Maksimovic wrote a really nice paper on an OCC boost converter about 10
years ago. I figured out how it works once, but carefully forgot most of
it. Basically its a non-linear modulating ramp, whose non-linearity is
carefully chosen to automagically achieve (in this case) UPF. Heck, I've
even seen an OCC paper by Slobodan Cuk.

The problem with OCC is that it requires integrators that get reset
every cycle. Thats not so bad, but (until now) you have had to DIY these
integrators. I have never built one to prove it, but I expect that
making a practical device work is a lot trickier than it appears from
the papers I have read (none of which give any detail of the resettable
integrators). I imagine that IR have done a nice job though.

Cheers
Terry
 
Terry Given wrote:
Harry Dellamano wrote:

IRF has introduced the IR1150S control IC. It contains a proprietary
"one cycle control" for CCM PFC with no line voltage sense required.
Pretty neat!
But, can't we also use it in any DC/DC CCM loop, be it forward,
flyback or boost as a voltage feedforward control loop without
actually looking at the input voltage. Even better, will this
controller not cure the dreaded Harmonic Oscillation in peak current
controlled CCM loops operated at >50% duty?
OMG, I just wet my pants.
What say you, you power supply gurus?
Cheers,
Harry


Keyue Smedley has written dozens of papers on one-cycle control; Dragan
Maksimovic wrote a really nice paper on an OCC boost converter about 10
years ago. I figured out how it works once, but carefully forgot most of
it. Basically its a non-linear modulating ramp, whose non-linearity is
carefully chosen to automagically achieve (in this case) UPF. Heck, I've
even seen an OCC paper by Slobodan Cuk.

The problem with OCC is that it requires integrators that get reset
every cycle. Thats not so bad, but (until now) you have had to DIY these
integrators. I have never built one to prove it, but I expect that
making a practical device work is a lot trickier than it appears from
the papers I have read (none of which give any detail of the resettable
integrators). I imagine that IR have done a nice job though.

Cheers
Terry
Click to expand...
Their PF isnt too good at low load, high line though, its about 0.828
for 30W = 10% rated load at 230V (cf 0.985 at 115V). Although they have
made little or no effort at controlling them, emissions are not bad.

I suspect the PF could be improved with peak input voltage feed-forward
of some description, but that might prove tricky as there is no access
to the on-chip integrators.

Cheers
Terry
 
"Harry Dellamano" <harryd@tdsystems.org> wrote in message
news:aJrXd.30028$QQ3.19113@trnddc02...
IRF has introduced the IR1150S control IC. It contains a proprietary "one
cycle control" for CCM PFC with no line voltage sense required. Pretty
neat!
But, can't we also use it in any DC/DC CCM loop, be it forward, flyback
or
boost as a voltage feedforward control loop without actually looking at
the
input voltage. Even better, will this controller not cure the dreaded
Harmonic Oscillation in peak current controlled CCM loops operated at >50%
duty?
OMG, I just wet my pants.
What say you, you power supply gurus?
Cheers,
Harry
Click to expand...
Fairchild FAN4803, PFC and OFFLINE current mode controller in an 8 pin
package.

Internally synchronized PFC and PWM in one 8-pin IC
Patented one-pin voltage error amplifier with advanced input current shaping
technique
Peak or average current, continuous boost, leading edge PFC (Input Current
Shaping Technology)
High efficiency trailing-edge current mode PWM
Low supply currents; start-up: 150ľA typ., operating: 2mA typ.
Synchronized leading and trailing edge modulation
Reduces ripple current in the storage capacitor between the PFC and PWM
sections
Overvoltage, UVLO, and brownout protection
PFC VCCOVP with PFC Soft Start

$1.24

DNA
 
On Wed, 09 Mar 2005 09:13:31 GMT, "Genome" <ilike_spam@yahoo.co.uk>
wrote:

"Harry Dellamano" <harryd@tdsystems.org> wrote in message
news:aJrXd.30028$QQ3.19113@trnddc02...
IRF has introduced the IR1150S control IC. It contains a proprietary "one
cycle control" for CCM PFC with no line voltage sense required. Pretty
neat!


Fairchild FAN4803, PFC and OFFLINE current mode controller in an 8 pin
package.

Internally synchronized PFC and PWM in one 8-pin IC
Patented one-pin voltage error amplifier with advanced input current shaping
technique
Peak or average current, continuous boost, leading edge PFC (Input Current
Shaping Technology)
High efficiency trailing-edge current mode PWM
Low supply currents; start-up: 150ľA typ., operating: 2mA typ.
Synchronized leading and trailing edge modulation
Reduces ripple current in the storage capacitor between the PFC and PWM
sections
Overvoltage, UVLO, and brownout protection
PFC VCCOVP with PFC Soft Start

$1.24
Click to expand...
Previously known as the ML4803.

RL
 
On Wed, 09 Mar 2005 19:27:29 GMT, "Harry Dellamano"
<harryd@tdsystems.org> wrote:

"Terry Given" <my_name@ieee.org> wrote in message
news:z2xXd.8135$1S4.858723@news.xtra.co.nz...
Harry Dellamano wrote:
IRF has introduced the IR1150S control IC. It contains a proprietary
"one cycle control" for CCM PFC with no line voltage sense required.
Pretty neat!
But, can't we also use it in any DC/DC CCM loop, be it forward, flyback
or boost as a voltage feedforward control loop without actually looking
at the input voltage. Even better, will this controller not cure the
dreaded Harmonic Oscillation in peak current controlled CCM loops
operated at >50% duty?
OMG, I just wet my pants.
What say you, you power supply gurus?
Cheers,
Harry

Keyue Smedley has written dozens of papers on one-cycle control; Dragan
Maksimovic wrote a really nice paper on an OCC boost converter about 10
years ago. I figured out how it works once, but carefully forgot most of
it. Basically its a non-linear modulating ramp, whose non-linearity is
carefully chosen to automagically achieve (in this case) UPF. Heck, I've
even seen an OCC paper by Slobodan Cuk.

The problem with OCC is that it requires integrators that get reset every
cycle. Thats not so bad, but (until now) you have had to DIY these

integrators. I have never built one to prove it, but I expect that making
a practical device work is a lot trickier than it appears from the papers
I have read (none of which give any detail of the resettable integrators).
I imagine that IR have done a nice job though.

Cheers
Terry

I like your "even....S.Cuk"
So Terry, will this controller cure sub harmonic oscillation in CCM >50%
duty??
What about using it's voltage feedforward ability in DC/DC loops?
Click to expand...
Which voltage?

Read and enjoy.

http://www.eng.uci.edu/faculty/smedley/occ.pdf
http://www.eng.uci.edu/~pelwww/ocamp.pdf
http://www.eng.uci.edu/~smedley/IPEMC-A185.PDF
http://ece-www.colorado.edu/~rwe/papers/PESC95.pdf
http://www.irf.com/technical-info/whitepaper/pcimeur03sccpfc.pdf

others
http://www.eng.uci.edu/faculty/smedley/index.html#sel
http://ece-www.colorado.edu/~pwrelect/publications.html

RL
 
Harry Dellamano wrote:
"Terry Given" <my_name@ieee.org> wrote in message
news:z2xXd.8135$1S4.858723@news.xtra.co.nz...

Harry Dellamano wrote:

IRF has introduced the IR1150S control IC. It contains a proprietary
"one cycle control" for CCM PFC with no line voltage sense required.
Pretty neat!
But, can't we also use it in any DC/DC CCM loop, be it forward, flyback
or boost as a voltage feedforward control loop without actually looking
at the input voltage. Even better, will this controller not cure the
dreaded Harmonic Oscillation in peak current controlled CCM loops
operated at >50% duty?
OMG, I just wet my pants.
What say you, you power supply gurus?
Cheers,
Harry

Keyue Smedley has written dozens of papers on one-cycle control; Dragan
Maksimovic wrote a really nice paper on an OCC boost converter about 10
years ago. I figured out how it works once, but carefully forgot most of
it. Basically its a non-linear modulating ramp, whose non-linearity is
carefully chosen to automagically achieve (in this case) UPF. Heck, I've
even seen an OCC paper by Slobodan Cuk.

The problem with OCC is that it requires integrators that get reset every
cycle. Thats not so bad, but (until now) you have had to DIY these


integrators. I have never built one to prove it, but I expect that making
a practical device work is a lot trickier than it appears from the papers
I have read (none of which give any detail of the resettable integrators).
I imagine that IR have done a nice job though.

Cheers
Terry


I like your "even....S.Cuk"
Click to expand...
Hey, if Dr Cuk writes papers on it, it probably works. Unlike much of
the crap published in some professional comics :), which look something
like this:

1. design a topology have way too many magnetic components, switches,
diodes and capacitors than necessary. If possible, ensure > 3
semiconductors in power path at all times.

2. write the NLTV equations for the system.

3. run thru maths package and draw pretty pictures

4. spice circuit - ie enter graphically, then let spice numerically
extract & solve much the same equations as (2), and draw some more
pretty pictures

5. Compare and contrast the pretty pictures. If they are very similar,
pat self on back and proudly announce "it works" (or in other words the
analytic solution mathced the numeric one)

6. Add to list of published papers, lean back at desk and sigh
contentedly. Outside, the real world rushes madly by.

So Terry, will this controller cure sub harmonic oscillation in CCM >50%
duty??
Click to expand...
I think in general it will do so, but you can perhaps design one that
doesnt.

OCC is by definition a non-linear controller, so there is no need to
"linearize" (read as: pretend it is something it is not) the system
before designing the controller. Quite the opposite in fact.

You design a One-Cycle Controller by developing a non-linear
time-varying mathematical description of the converter to be controlled.
We do this anyway when designing a conventional linear controller.

After adopting a suitable pose and expression, stare long and hard at
the mathematical description, and voila - the desired OCC control law
comes leaping out at you.

This is basically a kind of feedback linearization controller (eg
Applied Nonlinear Control, Slotine, pp207-271). The idea is to cancel
the nonlinearities in a nonlinear system so that the closed-loop
dynamics are in a linear form. Traditional LTI system theory can then be
used to design the controller, and assuming there are no model
uncertainties the controller behaves as predicted, for large as well as
small signals.

[linearisation is actually "do a taylor/maclaurin series expansion and
throw almost all of it away". Often the bits you discard are important,
which is why linearised controllers dont necessarily work so well for
say large signals]

A simple example of this concept is a boost PFC. When designing the
voltage control loop, if you use square of the DC bus voltage and
compare it with the square of the setpoint voltage (trivial in s/w) - in
other words implement a DC bus energy controller - then analysis shows
the closed loop behaviour is in fact linear (assuming the current
controller is fast enough to reach setpoint faster than the voltage loop
sample time).

Its interesting that one method of nonlinear stability analysis,
Lyapunovs 1st (or is it 2nd? someone will correct me im sure) method
uses suitable "lyapunov functions" to check asymptotic stability. Common
functions are the so-called "energy functions" that mathematically are
similar to physics equations for energy like 0.5CV^2 etc. Oops,
rambling...its because of the 2nd law of thermodynamics, real systems
are always asymptotically stable (if not they would be perpetual motion
or free energy machines) blurble.

that control systems label isnt necessarily right either - I suspect
some OCC designs may look more like a straight nonlinear controller
rather than the aforementioned feedback linearisation. who cares, its
only a label, but the techniques are interesting.

A significant drawback with non-linear control is the lack of a
handle-cranking mechanism for, say, proving stability, or even choosing
a controller. Its a big nasty world out there....time to go shelter
behing whats left of Maclaurin....


What about using it's voltage feedforward ability in DC/DC loops?

Regards,
Harry
Click to expand...
as usual, *it depends*. Each OCC strategy is (or can be) unique - define
your system, design the controller. A literature search will save you a
fair chunk of work here, but in practice if you're gonna design a loop
you might as well analyse the entire thing. Or at least load up the last
mathcad file, save as and twiddle the numbers....

One potential problem with feedback linearisation is its robustness to
parameter variations. Some implementations may be very sensitive, others
may not. The published results I've read for many OCC converters look
pretty good, probably because the integration smooths over any errors.
But I betcha you could come up with really lousy OCC's if you tried :)

I (hopefully) have a project coming up where I will implement a whole
raft of feedback linearisation controllers. Maybe they will even
work.....the idea is to implement non-linear controllers to enable the
system to maintain control (not saturate) for large setpoint & load
changes, along with a high closed-loop bandwidth for relatively low
sampling rates. This stuff (in some respects) is quite easy in a DSP,
whereas a lot of it is a pig in hardware (until IR, ST etc. make nice
cheap chips)

Cheers
Terry
 
Hello Terry,

Hey, if Dr Cuk writes papers on it, it probably works. Unlike much of
the crap published in some professional comics :), which look something
like this:

1. design a topology have way too many magnetic components, switches,
diodes and capacitors than necessary. If possible, ensure > 3
semiconductors in power path at all times.

2. write the NLTV equations for the system.

3. run thru maths package and draw pretty pictures

4. spice circuit - ie enter graphically, then let spice numerically
extract & solve much the same equations as (2), and draw some more
pretty pictures

5. Compare and contrast the pretty pictures. If they are very similar,
pat self on back and proudly announce "it works" (or in other words the
analytic solution mathced the numeric one)

6. Add to list of published papers, lean back at desk and sigh
contentedly. Outside, the real world rushes madly by.
Click to expand...
Or follow the route of the new age "instant design":

1. Key your parameters into a web interface and click.

2. Wait.

3. Wait some more.

4. Upon the message "parameters are outside the scope of this web design
program", "design cannot be completed with entered parameters" or
something like that, rip sheet off anger management pad on office wall.

3. Crumple anger management sheet and throw into corner of office. For
maximum relief, do so with gusto.

4. Roll your own design. Heck, maybe you don't even need any fancy
controller chip.

Regards, Joerg

http://www.analogconsultants.com
 
Joerg wrote:
Hello Terry,

Hey, if Dr Cuk writes papers on it, it probably works. Unlike much of
the crap published in some professional comics :), which look
something like this:

1. design a topology have way too many magnetic components, switches,
diodes and capacitors than necessary. If possible, ensure > 3
semiconductors in power path at all times.

2. write the NLTV equations for the system.

3. run thru maths package and draw pretty pictures

4. spice circuit - ie enter graphically, then let spice numerically
extract & solve much the same equations as (2), and draw some more
pretty pictures

5. Compare and contrast the pretty pictures. If they are very similar,
pat self on back and proudly announce "it works" (or in other words
the analytic solution mathced the numeric one)

6. Add to list of published papers, lean back at desk and sigh
contentedly. Outside, the real world rushes madly by.


Or follow the route of the new age "instant design":

1. Key your parameters into a web interface and click.

2. Wait.

3. Wait some more.

4. Upon the message "parameters are outside the scope of this web design
program", "design cannot be completed with entered parameters" or
something like that, rip sheet off anger management pad on office wall.

3. Crumple anger management sheet and throw into corner of office. For
maximum relief, do so with gusto.

4. Roll your own design. Heck, maybe you don't even need any fancy
controller chip.

Regards, Joerg

http://www.analogconsultants.com
Click to expand...
ROTFLMAO!

Cheers
Terry
 
"legg" <legg@nospam.magma.ca> wrote in message
news:458v215k5cqfsd1osfgoruh76q7kj419rg@4ax.com...
On Wed, 09 Mar 2005 19:27:29 GMT, "Harry Dellamano"
harryd@tdsystems.org> wrote:


"Terry Given" <my_name@ieee.org> wrote in message
news:z2xXd.8135$1S4.858723@news.xtra.co.nz...
Harry Dellamano wrote:
IRF has introduced the IR1150S control IC. It contains a proprietary
"one cycle control" for CCM PFC with no line voltage sense required.
Pretty neat!
But, can't we also use it in any DC/DC CCM loop, be it forward,
flyback
or boost as a voltage feedforward control loop without actually looking
at the input voltage. Even better, will this controller not cure the
dreaded Harmonic Oscillation in peak current controlled CCM loops
operated at >50% duty?
OMG, I just wet my pants.
What say you, you power supply gurus?
Cheers,
Harry

Keyue Smedley has written dozens of papers on one-cycle control; Dragan
Maksimovic wrote a really nice paper on an OCC boost converter about 10
years ago. I figured out how it works once, but carefully forgot most of
it. Basically its a non-linear modulating ramp, whose non-linearity is
carefully chosen to automagically achieve (in this case) UPF. Heck, I've
even seen an OCC paper by Slobodan Cuk.

The problem with OCC is that it requires integrators that get reset
every
cycle. Thats not so bad, but (until now) you have had to DIY these

integrators. I have never built one to prove it, but I expect that
making
a practical device work is a lot trickier than it appears from the
papers
I have read (none of which give any detail of the resettable
integrators).
I imagine that IR have done a nice job though.

Cheers
Terry

I like your "even....S.Cuk"
So Terry, will this controller cure sub harmonic oscillation in CCM >50%
duty??
What about using it's voltage feedforward ability in DC/DC loops?


Which voltage?

Read and enjoy.

http://www.eng.uci.edu/faculty/smedley/occ.pdf
http://www.eng.uci.edu/~pelwww/ocamp.pdf
http://www.eng.uci.edu/~smedley/IPEMC-A185.PDF
http://ece-www.colorado.edu/~rwe/papers/PESC95.pdf
http://www.irf.com/technical-info/whitepaper/pcimeur03sccpfc.pdf

others
http://www.eng.uci.edu/faculty/smedley/index.html#sel
http://ece-www.colorado.edu/~pwrelect/publications.html

RL
Click to expand...
Great reading RL, thanks. This will fill a missing part of my knowledge.
Harry
 
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