1. Home
  2. Electronics Design
  3. diffamp with Vcc = 0

diffamp with Vcc = 0

This is sort of cute. The amps have their collector resistors returned to ground, so they are running with collector voltages below their base voltages.

formatting link

The transistors are almost saturated (they are, by some definitions) but the voltage gains are still roughly as predicted by the old EROT, gain = collector resistor drop times 40. If the transistor models are good.

Version 4 SHEET 1 1348 680 WIRE 1056 -432 944 -432 WIRE 1152 -432 1056 -432 WIRE 1056 -400 1056 -432 WIRE 944 -304 944 -432 WIRE 1152 -304 1152 -432 WIRE 272 -272 160 -272 WIRE 368 -272 272 -272 WIRE 272 -240 272 -272 WIRE 944 -192 944 -224 WIRE 1280 -192 944 -192 WIRE 1344 -192 1280 -192 WIRE 160 -144 160 -272 WIRE 368 -144 368 -272 WIRE 1152 -128 1152 -224 WIRE 1280 -128 1152 -128 WIRE 1344 -128 1280 -128 WIRE 944 -80 944 -192 WIRE 1152 -80 1152 -128 WIRE 160 -32 160 -64 WIRE 464 -32 160 -32 WIRE 880 -32 464 -32 WIRE 1296 -32 1216 -32 WIRE 368 32 368 -64 WIRE 464 32 368 32 WIRE 736 32 464 32 WIRE 944 48 944 16 WIRE 992 48 944 48 WIRE 1040 48 992 48 WIRE 1152 48 1152 16 WIRE 1152 48 1040 48 WIRE 160 80 160 -32 WIRE 368 80 368 32 WIRE 736 112 736 32 WIRE 1296 112 1296 -32 WIRE 1296 112 736 112 WIRE 0 128 -80 128 WIRE 96 128 0 128 WIRE 512 128 432 128 WIRE -80 192 -80 128 WIRE 160 208 160 176 WIRE 224 208 160 208 WIRE 256 208 224 208 WIRE 368 208 368 176 WIRE 368 208 256 208 WIRE 512 208 512 128 WIRE 256 240 256 208 WIRE 1040 240 1040 48 WIRE -80 320 -80 272 WIRE 256 368 256 320 WIRE 1040 368 1040 320 WIRE 1040 368 256 368 WIRE 256 400 256 368 WIRE 256 528 256 480 FLAG -80 320 0 FLAG 272 -240 0 FLAG 256 528 0 FLAG 512 208 0 FLAG 0 128 IN FLAG 464 -32 X FLAG 464 32 Y FLAG 1056 -400 0 FLAG 224 208 E1 FLAG 1280 -192 A FLAG 1280 -128 B FLAG 992 48 E2 FLAG 0 0 E2 SYMBOL npn 96 80 R0 WINDOW 0 87 20 Left 2 WINDOW 3 64 55 Left 2 SYMATTR InstName Q1 SYMATTR Value 2N4401 SYMBOL npn 432 80 M0 WINDOW 0 96 20 Left 2 WINDOW 3 73 55 Left 2 SYMATTR InstName Q2 SYMATTR Value 2N4401 SYMBOL res 240 224 R0 WINDOW 0 64 42 Left 2 WINDOW 3 60 76 Left 2 SYMATTR InstName R1 SYMATTR Value 75K SYMBOL res 144 -160 R0 WINDOW 0 -56 34 Left 2 WINDOW 3 -64 78 Left 2 SYMATTR InstName R2 SYMATTR Value 10K SYMBOL res 352 -160 R0 WINDOW 0 -58 31 Left 2 WINDOW 3 -64 72 Left 2 SYMATTR InstName R3 SYMATTR Value 10K SYMBOL voltage -80 176 R0 WINDOW 0 47 53 Left 2 WINDOW 3 -47 199 Left 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value SINE(0 1m 1K) SYMBOL voltage 256 384 R0 WINDOW 0 66 41 Left 2 WINDOW 3 64 77 Left 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V2 SYMATTR Value -5 SYMBOL npn 880 -80 R0 WINDOW 0 99 23 Left 2 WINDOW 3 75 58 Left 2 SYMATTR InstName Q3 SYMATTR Value 2N4401 SYMBOL npn 1216 -80 M0 WINDOW 0 102 21 Left 2 WINDOW 3 74 58 Left 2 SYMATTR InstName Q4 SYMATTR Value 2N4401 SYMBOL res 1024 224 R0 WINDOW 0 82 33 Left 2 WINDOW 3 78 68 Left 2 SYMATTR InstName R4 SYMATTR Value 50K SYMBOL res 928 -320 R0 WINDOW 0 -58 36 Left 2 WINDOW 3 -64 72 Left 2 SYMATTR InstName R5 SYMATTR Value 10K SYMBOL res 1136 -320 R0 WINDOW 0 -54 34 Left 2 WINDOW 3 -58 71 Left 2 SYMATTR InstName R6 SYMATTR Value 10K TEXT 568 -216 Left 2 !.tran 0.005 TEXT 544 -392 Left 2 ;VCC = 0 DIFFAMP TEXT 544 -344 Left 2 ;JL May 24 2013

If I flip this idea over, I can do my mosfet realtime power dissipation multiplier thing without a negative power supply.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators
Reply to
John Larkin
Loading thread data ...

[snip]

Sonnuva gun! Freshman student Larkin is just now (?) discovering what all the rest of us knew >:-}

Anyone who has curve-traced a transistor knows that!

Next Larkin will proclaim surprise that a grounded base transistor configuration, with base tied to ground, can swing below ground.

Sonnuva gun! ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

voltages.

collector

This IS a circuit DESIGN discussion group, is it not?

If Larkin wants to proclaim "cute", let it be on sci.electronics.basics ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

voltages.

collector

Given Larkin's heavy use of PECL, ECL and CML, one might even make a case for plagiarism >:-} ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

voltages.

formatting link

the

collector

Most classic 10K ECL parts would malfunction if a logic input got close to ground. Nominal logic high was about -0.8 volts, and most would fold over at -0.4 or so. Newer parts generally accept ground as a logic high.

Jim isn't interested in discussing electronics. He only wants to shout how smart he is, or, preferably, how dumb other people are. Note that his posts seldom have technical content. Do you think that's cute?

I'm still playing with the mosfet power dissipation multiplier idea, the realtime analog SOAR computation.

--

John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation
Reply to
John Larkin

voltages.

formatting link

the

collector

Sticking to technology, look up CML. Larkin mis-addresses (probably purposefully) the topic. The discussion is in regard to collector-base potential.

Larkin still hasn't figured out how to undo the 90-degree locking feature... now THAT is really cute >:-} ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

Got any good techniques to remove rust stains from ceramic floor tiles?

--

John Larkin Highland Technology, Inc

jlarkin at highlandtechnology dot com

formatting link

Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation

Reply to
John Larkin

I can't help it if they're dumb.

"Cute" is a royally dumb-ass statement. ...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

formatting link
| 1962 | I love to cook with wine. Sometimes I even put it in the food.

Reply to
Jim Thompson

As others have pointed out, Naval Jelly works... it's phosphoric acid solutino, with a gelling additive.

I've heard of people using oxalic acid, citric acid, and ascorbic acid (Vitamin C powder) in the same fashion. They all reduce the rust to a more soluble and less colored form.

All of these have some ability to etch concrete and probably other ceramics. The liquid phosphoric acid solution I use to de-rust tools is also advertised as a "concrete etch" to be used before painting, and it really does make the concrete foam aggressively when it hits! Glazed tiles may be less vulnerable, but you never know! It would probably be a good idea to test any such acid in an inconspicuous corner of the room and see if the tile suffers from any etching which would be more unsightly than the stain. You may find that the tile survives OK but the grout is damaged, and would need to be cut out and replaced.

(In other words, mount a scratch monkey before running diagnostics :-)

Really severe cases may have no solution which doesn't involve the use of a grout saw, hammer and chisel, and a set of replacement tiles.

--
Dave Platt                                    AE6EO 
Friends of Jade Warrior home page:  http://www.radagast.org/jade-warrior 
  I do _not_ wish to receive unsolicited commercial email, and I will 
     boycott any company which has the gall to send me such ads!
Reply to
Dave Platt

That was just an interesting aside to this:

formatting link

It doesn't need a negative power supply, and power dissipation is tiny in the PNP pair - Vce is tenths of a volt - so self-heating won't cause any errors to speak of. Works pretty well in simulation.

--

John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation
Reply to
John Larkin

I'd be wary of trusting the models provided by LTspice... they tend to be too perfect.

As I noted in a comparison posted in...

Subject: Re: spec out low power bjt Date: Sun, 12 May 2013 10:31:52 -0700 Message-ID:

I'd use device models from the manufacturer.

A quick check of a 2N3906, running at IC = ~20uA, would indicate you need about 0.3V VCE to allow around a +/- 0.1V swing without hitting the "knee", which fits with my general rule of thumb of 1/2 Vbe.

Cascodes are another animal altogether... you can push pretty close to VCE = 0.1 on the cascoded device without problem. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

No, I don't have rusty floor tiles; Jim does. That's about all he has to post about any more, that and redneck political rants.

I never understood why anybody would want an aquarium. Fish are messy and not very affectionate.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators
Reply to
John Larkin

Strange accusation, since the last few posts of his I glanced at,

*before* I read this tripe of yours were absolutely about electronics.
Reply to
DecadentLinuxUserNumeroUno

Ya, I saw Jim's post after I made my post. I have no interest in having fish, except for dinner. However, to each there own. Like my wife, she loves to spend hours picking weeds out of the lawn, me, not a chance. Mikek

Reply to
amdx

Then you have selective vision.

Jamie

Reply to
Jamie

[snip]
[snip]

Either Larkin, and his Pecksniffian echoes are either misinformed, or are liars.

In the past 4 years I've posted 948 links to schematics on my website (with component values :), 42 in the last few months. (464 Schematics are still available on the site.)

I've also posted 34 links to other sites to provide answers to questions that were posed here.

I've also posted 114 device/transistor models that people were having trouble finding.

Also 38 subcircuit/behavioral models.

Where the real designers with a real interest in electronics hang out, the LTspice/SwitcherCAD III Group, I've made 81 posts in the last year. That's where John Woodgate now posts.

Larkin says, "Jim isn't interested in discussing electronics."

That's patently false. What hurts his little-bitty feelings is any criticism of his sketches (without component values :). In fact, I can't recall ANY schematic posted by Larkin the included values. That's how he avoids (or try's to avoid) any criticism or VERIFICATION

Now that I've made my spiel, I'll shut up.

Except, please note, Larkin's "technical" posts will continue to be criticized where appropriate, irrespective of any snarky responses from Larkin or his sycophants.

Snarkiness will be ignored. Larkin thinks his snarkiness impresses. (Probably only his sycophants.)

I do note a Larkin success: It appears that he has scared off a large number of lurkers from posting, for fear of a Larkin-dump. I get several E-mails a week from people whose names I don't even recognize, requesting circuit assistance. Recently I've even been getting phone calls for help.

If any of you wish help, just E-mail or call. I always respond... it's fun ;-)

I'll be re-writing my webpage mail-box to delete the reference telling students to come here for help. With the likes of Larkin and his sycophants, this is the worst place for a novice to come. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| Phoenix, Arizona  85048    Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

Hilarious. If I post a sketch without parts values, Thompson is helpless to figure out if it can work or not. He can't understand circuits using his own brain, and can't figure out working values for himself. Apparently all he knows how to do is plug Heathkit circuits into Spice and see if they work.

Worst of all, he won't play the circuit game, won't contribute positively to evolving ideas, he has no ideas, and he posts nothing original. He's sort of a monolithic silicon technician.

Unlikely.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators
Reply to
John Larkin

Try posting a schematic in even so much as what is considered to be an acceptable rough draft format, and we'll shut up.

Even the roughest 'guesstimator' puts in rough default starting values.So even your argument in that regard falls flat on its face.

But I wouldn't know the first thing about philosophy, since I am universally philtered.

Reply to
DecadentLinuxUserNumeroUno

knows

Sounds like you can't visualize circuit function either. That's OK, most people can't. Like most people don't know the difference between a watt and a joule.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators
Reply to
John Larkin

After looking at, designing, adjusting, testing, and proofing tiny GHz tank circuits and strip line features in 0204 form factors on mil 'blade' paradigm circuit cards, I think I have basic visualization down, since none of those parts are marked and circuit pathways are easy to follow on RF schematics. Not so easy on PWAs where most if not all of the traces are on sub-surface layers.

Those are very dense circuit cards too. Full of expensive, specialized filter, amp, and stimulator/synthesizer modules, most not much bigger than a low profile matchbox. All surrounded by tiny 0402 and 0201 parts, making servicing and setting up test pathways a real joy. All on a card that is about 5" x 7".

The big blades I work on are like 10" x 11" and go into big Radisys chassis (commercial gear so I can talk about vendors). Those are our designs.

We also buy huge HP blade server chassis and fill 'em up with $5000 Dual Xeon server blades for about 24 cores worth of processing on each blade, and we get their 1U and 2U computers too, which are really nice pieces.

And we buy 10Gb/s Juniper Optical fiber fabric chassis and blades which are even bigger at like 18" by 12". Those are in the $ hundreds of thousands each range. Hell, each optical port is $1000.

I think I can visualize a circuit path, Johnny. I work with the most cutting edge circuit pathways on the planet (and through its airwaves).

A watt expresses a rate of consumption. As in how much work is being done how quickly, i.e. "rate of consumption". Should correctly be referred to as "watt hour", verbally speaking. In math, the watt/hour.

Whereas a joule is usually an expression of the entirety of the amount of energy an observed event consumed. In other words, how much work was done.

Try again, child.

Reply to
DecadentLinuxUserNumeroUno

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.