Circuit Contest - Last Day

[Jim Thompson]

Monday, October 31, is the last day for submission to the first
circuit analysis/design contest.

So far only two reasonable submissions for Circuit1. None for the
others.

No surprise. I figured as much :-(

...Jim Thompson

 

[Tim Williams]

Monday, October 31, is the last day for submission to the first
circuit analysis/design contest.

Humm what is this, anything and everything? How about this then?
http://webpages.charter.net/dawill/Images/Tube PWM Generator.gif

Tim

 

[Winfield Hill]

Tim Williams wrote...

Humm what is this, anything and everything? How about this then?
http://webpages.charter.net/dawill/Images/Tube PWM Generator.gif

Sawtooth oscillator (freq set by Rt-Ct ramp, hysteresis
comparator, and discharge) plus PWM-generator comparator.

Sig in and PWM output. Yawn.

 

[Tim Williams]

Sawtooth oscillator (freq set by Rt-Ct ramp, hysteresis
comparator, and discharge) plus PWM-generator comparator.

Sig in and PWM output. Yawn.

Yeah, but it's tube, and I'd like some precise numbers. ;-)

Tim

 

[Fred Bloggs]

Monday, October 31, is the last day for submission to the first
circuit analysis/design contest.

So far only two reasonable submissions for Circuit1. None for the
others.

No surprise. I figured as much :-(

...Jim Thompson

Yep- that's about right. Maybe you should try changing the angle of this
"contest" to invention instead of straightforward circuit analysis. The
ignorant losers, who comprise the majority of SED, will be self-excluded
still, but the competent enthusiasts at all levels can compete.

 

[Winfield Hill]

Tim Williams wrote...

Winfield Hill wrote ...

Yeah, but it's tube, and I'd like some precise numbers. ;-)

Fine, then get busy and do the work, we're not going to. ;-)
http://webpages.charter.net/dawill/Images/Tube PWM Generator.gif

 

[Andrew Holme]

Monday, October 31, is the last day for submission to the first
circuit analysis/design contest.

So far only two reasonable submissions for Circuit1. None for the
others.

No surprise. I figured as much :-(

You might not have many responses, but I'm sure I'm not the only person
waiting to be enlightened, whose curiosity was aroused by one or other
of the circuits. I puzzled over the logic buffer circuit for a while,
but I couldn't fathom its purpose: speeding up the edges? Slowing down
the edges?? Controlling the thresholds??? So I hope you're going to
educate us in due course.

 

[Winfield Hill]

Andrew Holme wrote...

You might not have many responses, but I'm sure I'm not the only person
waiting to be enlightened, whose curiosity was aroused by one or other
of the circuits. I puzzled over the logic buffer circuit for a while,
but I couldn't fathom its purpose: speeding up the edges? Slowing down
the edges?? Controlling the thresholds??? So I hope you're going to
educate us in due course.

I couldn't even find the file, so clearly I was out of it. : )

 

[Jim Thompson]

You might not have many responses, but I'm sure I'm not the only person
waiting to be enlightened, whose curiosity was aroused by one or other
of the circuits. I puzzled over the logic buffer circuit for a while,
but I couldn't fathom its purpose: speeding up the edges? Slowing down
the edges?? Controlling the thresholds??? So I hope you're going to
educate us in due course.

Yes, I will post functional descriptions in a few days.

...Jim Thompson

 

[Jim Thompson]

Andrew Holme wrote...

I couldn't even find the file, so clearly I was out of it. : )

Originally posted to A.B.S.E with an announcement on S.E.D to go to
A.B.S.E

When many didn't get A.B.S.E on their servers I also announced and
posted a URL...

http://www.analog-innovations.com/SED/Contest1.zip

...Jim Thompson

 

[Jim Thompson]

Yep- that's about right. Maybe you should try changing the angle of this
"contest" to invention instead of straightforward circuit analysis. The
ignorant losers, who comprise the majority of SED, will be self-excluded
still, but the competent enthusiasts at all levels can compete.

Well. I need a bandgap that will run on +1.62V, from -55°C to +125°C,
CMOS process with parasitic substrate PNP's ;-)

...Jim Thompson

 

[Winfield Hill]

Jim Thompson wrote...

Well. I need a bandgap that will run on +1.62V, from -55°C to +125°C,
CMOS process with parasitic substrate PNP's ;-)

That's fine, we can design you one, but you'll have to linearize it.

 

[John Popelish]

You might not have many responses, but I'm sure I'm not the only person
waiting to be enlightened, whose curiosity was aroused by one or other
of the circuits. I puzzled over the logic buffer circuit for a while,
but I couldn't fathom its purpose: speeding up the edges? Slowing down
the edges?? Controlling the thresholds??? So I hope you're going to
educate us in due course.

I'm not at all certain that educating us is the primary Jim's
motivation for the contest.

 

[Jim Thompson]

Jim Thompson wrote...

That's fine, we can design you one, but you'll have to linearize it.

A bandgap is supposed to be flat over temperature and VDD ;-)

...Jim Thompson

 

[Jim Thompson]

I'm not at all certain that educating us is the primary Jim's
motivation for the contest.

It IS primarily for educational purposes, although an ulterior motive
lurked in the back of my head... demonstrate that several of the key
noise-makers lurking here are blow-hards ;-)

(NONE of the key noise-makers submitted a circuit analysis.)

...Jim Thompson

 

[Jim Thompson]

It IS primarily for educational purposes, although an ulterior motive
lurked in the back of my head... demonstrate that several of the key
noise-makers lurking here are blow-hards ;-)

(NONE of the key noise-makers submitted a circuit analysis.)

...Jim Thompson

I should have added, ALL three of the circuits were really quite
simple, except for being typically monolithic... using lots of devices
to ensure matching and good temperature behavior, and with current
mirrors out the kazoo. The functions they performed should have been
"intuitively obvious to the most casual observer" ;-)

...Jim Thompson

 

[Winfield Hill]

Jim Thompson wrote...
I hope you weren't including me in that list. I can readily tell
what all three circuits do, and think I could correctly analyze 95
to 100% of the circuitry, but I also see it'd be a bit more time-
consuming than I'd like to spend right now. And frankly, not that
much fun either. I'm also unsure of what some of the intrinsic
capacitance values are. Sorry, Jim.

I do like your obsessive use of mirrors, that simplifies analysis.

 

[Joerg]

Hello Jim,

I should have added, ALL three of the circuits were really quite
simple, except for being typically monolithic... using lots of devices
to ensure matching and good temperature behavior, and with current
mirrors out the kazoo. The functions they performed should have been
"intuitively obvious to the most casual observer" ;-)

Ok, but since yesterday was the "last day", who won?

Regards, Joerg

 

[Winfield Hill]

Jim Thompson wrote...

A bandgap is supposed to be flat over temperature and VDD ;-)

--- ^^^^^^^^

Operative word. Perfectly flat.

 

[Jim Thompson]

Hello Jim,


Ok, but since yesterday was the "last day", who won?

Regards, Joerg

I need to carefully read over the three rational submissions and then
decide. (I had one very irrational submission from guess who ?

I purposefully refrained from more than glancing at the submissions as
they arrived. Since this is basically an "essay" question I want to
read all in one sitting so that I'm fair... "grading on the curve" ;-)

...Jim Thompson