1. Home
  2. Electronics Design
  3. Analog dynamic range, accuracy and number of bits
  4. Page 6

Analog dynamic range, accuracy and number of bits

message

the

cultural

engineering

I got involved in an FTMS system a couple of years ago. The preamp was designed by chemists, and they gave up about 30 dB of s/n, out of sheer generosity.

formatting link

formatting link

formatting link

formatting link

formatting link

The customer was IonSpec, who was acquired by Varian, and the FTMS operation was shut down when Agilent acquired Varian. Pity; I had a really cool preamp ready to go. Low noise, lots of gain, high z-in, and fast recovery from the big transmit pulse.

The old preamp used jfet opamp followers, hand-wired on a ceramic slab. In vacuum, they ran maybe 130C, no cooling, so they had to add

1M resistors to ground to soak up the gate leakage. Johnson noise like all get-out.

I wanted to detect a single molecule in orbit; it's barely possible.

--

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 ...

the

^^^^^^^^^^ monotonic, though that is rather boring.

Spell checkers canbestupid.

Reply to
josephkk

It makes a big difference when you average, integrate, or both. As for motor or electronic loads, just pay attention to the difference between W and VA with or without scaling prefixes. The abrupt popularity of PFC circuits is due to new regulations about harmonics introduction from the served loads (see CFL lamps which must include PFC).

needed

Reply to
josephkk

interest).

make

Signed? Really? I don't think so. Just for fun i checked wikipedia, is reasonably good on this point.

formatting link

?-)

Reply to
josephkk

the

think

interest).

make

be

You are conflating phase sign conventions with the unsigned PF value.

Not in the least applicable to real measurements. The definition is what it is. Your wishing it otherwise to support your position is foolish.

?-)

Reply to
josephkk

the

It is pretty simple John Larkin, You tried to say that PF is signed, wikipedia, and its cited sources all disagree with that. The NEC (NFPA

70) disagrees with that, ANSI C2 (NESC) disagrees with that. You choose what to say now.

?-)

Reply to
josephkk

will be

meaning

peaks

about

this

or

with

into

on

Wikipedia

Not arguing with that, arguing over whether that is a signed quantity, which cannot be from the definition.

?-)

Reply to
josephkk

But that is NOT part of the standard definition of power factor. See NFPA

70 (NEC), ANSI C2 (NESC), IEEE 100 for proper definitions. None of them produce signed values.

?-)

Reply to
josephkk

more

John Larkin is NOT someone to defer to in power distribution in anything bigger than a VME box. Not that he wrong, but that he is NOT expert in that field. I blow his doors off and i do not consider myself all that expert in spite of having dealt with designs for 480 V, 2 MVA systems,

12.47 kV 50 MVA systems, and other things of similar size and many more down to 120/240 V 50 A services, and down to PoE (about 50 VA max) and SMPTE-170 video (1V P-P 75 ohms) and even smaller signals in the same location. This a few feet apart, all of these, in the same location.

?-)

Reply to
josephkk

Don't forget to check out the TALK page on Wikipedia. There is certainly a LOT of talk about this very subject there too.

Some of it comes down to be Leading/Lagging rather than + and - and whether "power" can flow from a source and back into a source.

Also talked about are various power meters that DO show + and - PF readings.

boB

Reply to
bob K7IQ

Is COS(theta) signed?

Reply to
krw

You can make an inductor, but not an LC transmission line. On-chip wires are all RC.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

message

the

cultural

engineering

really

If you can look at it many times, it isn't so hard. This one is sort of a klystron type thing using an electron gun to make the ions--you tickle the trap with a chirp, and different charge/mass ratios come out at different times. They fiddled with it to make it work, and have sold quite a few of them, but don't have a warm fuzzy feeling about why it works or how to make it better.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

Dr. H. Paul Shuch wrote that he avoids using the expression "voltage" to differentiate between parameters and units of measure. He says that the parameter EMF (electric potential) is measured in the unit volt.

Sounded good to me, so I once tried displaying "EMF = xxx volts" on an LCD. They said no way. Show it as "Voltage = xxx volts".

Reply to
John S

No. Just very low inductance... in the fractional nH range. And some processes have _fully_characterized_ spiral inductors in the 4-10nH range

...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     | 
| Analog Innovations, Inc.                         |     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

EMF is a stupid term anyway. It doesn't have the units of a force, for a start, and force is far more closely related to E field than to voltage.

'Potential' is more sensible, but its common use as a vague vernacular term makes it unsuitable, e.g. "Wow, this circuit has a great deal of potential." 'Voltage' is the best term on offer.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

I used to be an RF guy in a previous life, so I know about on-chip inductors.

You're talking inductors, and I'm talking _transmission_lines_, because we started with wave propagation and Fourier transform sign conventions. Show me an LC transmission line on a chip, any chip.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

I'm puzzling over what point you're trying to make. There's certainly inductance there, it's just swamped by the resistive term. ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     | 
| Analog Innovations, Inc.                         |     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

There are some distributed-amplifier chips that do have on-chip delay lines. Some of the e/o modulator drivers make 8 volts p-p outputs from LF to 40 GHz.

--

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

They are rare, but a few exist. Here's one:

formatting link

We've used similar, Hittite chips as eom drivers. They are expensive and tricky to bias and kind of fragile.

--

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

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.