Burr Brown Chips

  • Thread starter Thread starter tkingen
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Minion said:
Here is the design I am useing ,It is basicly the datasheet design with a Basic ballanced line driver at the output to create a ballanced output....I am also useing 10K Reverse Log taper pots for Gain Controll.....


In my design I am not useing a OPA137 for DC offset but a Dual TL072 which are much cheaper and I am useing a Dual opamp because it does the DC Offset for 2 Channels..... I have allready designed the 2 channel PCB and etched a couple PCB"s and I am just waiting for some Parts to show up before stuffing the Boards......

Cheers
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Let us know how that works. I have aquired a bunch of parts to make the same basic design. But, I really need a microphone pre-amp I can use that runs on 12v DC, in the field. I don't know enough about electronics design to engineer a 12v power supply that will work with the INA217.
 
Minion said:
Here is the PSU that I use with my Preamps...

It uses the Much Quieter LM317/337 regulators and output Voltage is totally adjustable by simply changeing the Value of one resistor....


:)
Click to expand...

Where can I get one of those PCBs?
 
Minion said:
Here is the PSU that I use with my Preamps...

It uses the Much Quieter LM317/337 regulators and output Voltage is totally adjustable by simply changeing the Value of one resistor....
Click to expand...

It wouldn't be a terrible idea for apl to throw some filtration on the output of the regulators . . .
 
TaperChuck said:
Let us know how that works. I have aquired a bunch of parts to make the same basic design. But, I really need a microphone pre-amp I can use that runs on 12v DC, in the field. I don't know enough about electronics design to engineer a 12v power supply that will work with the INA217.
Click to expand...

There are some DC-DC converters from Maxim that are slick but way tiny, but I think you can get SMD adapters from Schmartboard that are easy to solder.
 
mshilarious said:
It wouldn't be a terrible idea for apl to throw some filtration on the output of the regulators . . .
Click to expand...

We'll see how noisy they are first. Besides, the pre circuit's got some filtering going on, too.
 
TaperChuck said:
Let us know how that works. I have aquired a bunch of parts to make the same basic design. But, I really need a microphone pre-amp I can use that runs on 12v DC, in the field. I don't know enough about electronics design to engineer a 12v power supply that will work with the INA217.
Click to expand...

Since you don't have an inverting supply, you ground the V- input, and bias the inputs at 1/2 the supply voltage. You will have reduced headroom because you have a lower input voltage, but everything else should work fine. You do need to check the datasheet for the chip to see if it will work OK at that voltage, but I think most of them do.

Edit: or yeah, you can add a DC-DC converter. I tend not to think about them because I can't use them in my designs. However 12V should be enough for -10dBV operation.
 
From looking at the INA217 Datasheet It doesn"t Indicate that it will work with a Single Voltage Supply...It just says that it will work from a +/-4.5v to +/-18v, Usually it will say that is works on a Single Supply and a Dual Supply so I would investigate further to see if it will actually work on a Single Supply rail....
Actually from looking at the Datasheet again I don"t think it will run on a Single supply, If you look at the "Input Voltage Range" of the Datasheet is only specifies +/- Voltages, If it did run off of a Single Supply it would Have stats for running off of a single supply like most datasheets, also none of the Circuits in the Datasheet have a single supply....

There are Lots of Low power discrete designs that will run off of a 9v Battery, If you want me to post a couple schematics 4 you let me know....


:)
 
i think almost any ic op amp

can be run from a single supply (of adequate voltage)

as long as you use dc blocking caps

on the input and output to the circuit

"A single-supply circuit (right side of Figure 1) connects the op-amp power pins to a positive voltage and ground. The positive voltage is connected to VCC+, and ground is connected to VCCor GND. A virtual ground, halfway between the positive supply voltage and ground, is the reference for the input and output voltages. The voltage swings above and below this virtual ground to the limit of VOM±. Some newer op amps have different high- and low-voltage rails, which are specified in data sheets as VOH and VOL, respectively. It is important to note that there are very few cases when the designer has the liberty to reference the input and output to the
virtual ground. In most cases, the input and output will be referenced to system ground, and the designer must use decoupling capacitors to isolate the dc potential of the virtual ground from the input and output (see section 1.3)."

lots more here, with circuit examples (ti ap report)
http://focus.ti.com/lit/an/sloa058/sloa058.pdf
 
tkingen said:
Any difference in sound between the INA217 and INA163?
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The specs are identical for the two, except for a slight difference in S/N. I believe that they are the same exact chip in different packaging. The 163 was already in production when Burr Brown realized that by repackaging it they could create a drop in replacement for the SSM2017, which wasn't very highly regarded. They saw a market opportunity.
 
I wonder if calling them TI instead of Burr Brown gives us a different perceived quality.
 
apl said:
Where can I get one of those PCBs?
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That's a Peter Cornell design, as is it'll only give you +/- 15v (plus 48v of course) , MSH or someone might be able to advise on getting up to +/-18v using different regulators or something if that's what you need. Or you could even try mailing Peter.

http://1176neve.tripod.com/id26.html

If you could use one and you can't find a supplier in the US PM me your address and I'll flick you one across the pond.
 
Kevin DeSchwazi said:
That's a Peter Cornell design, as is it'll only give you +/- 15v (plus 48v of course) , MSH or someone might be able to advise on getting up to +/-18v using different regulators or something if that's what you need...
Click to expand...
it looks like a simple substitution of 2.7k resistors

for r1 and r5 will bring the output voltage to +/- 18v



the +/- 15v power transformer t2 (where is t1?)

will give an unloaded dc output of about +/- 21v

so at low currents you wouldn't even have to substitute transformers

however, it would be best to do so



the transformer's rated voltage should be

+/- 20v or less - otherwise the phantom regulator (u3)

might see more than 88v at its input

(after voltage tripling by d2-d4, c11-c13)

and the max vout - vin differential

is 40v per the lm317 spec

http://www.x-robotics.com/downloads/datasheets/LM117.pdf


and it would be prudent to increase the voltage rating

on c12 to 100v also



i'm not an ee

so if this info is in error

please point it out :)



edit - here's the circuit, if anybody is wondering...
 

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apl said:
Where can I get one of those PCBs?
Click to expand...

Yes that is one of peter cornells designs, the creator of the Green Preamp....

You can buy Power supply Kits of this type over at the prodigy Pro forum but I suggest that you just use the PCB design I posted and just etch your own PCB ,That is what I do and it is Very easy , I actually have never used a profesinally etched PCB as I etch all of my own as it is Just so easy to do....
also to change it to a +/-18v supply you just have to change the Value of one resistor on each of the Power rails.....

:)
 
apl said:
I'm using a doubler on the 40VAC taps and then regulating down to 48V.

I just expected that there would be something like a ±15V/+48V module readily available.
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Why use +48Vdc? Use 80vDC. More Headroom.
 
MCI2424 said:
Why use +48Vdc? Use 80vDC. More Headroom.
Click to expand...

Oversupplying phantom will do nothing to a regulated microphone design, and could be dangerous to many designs. Further, even if the circuit wasn't damaged by the higher voltage, it is not necessarily true that greater headroom would be the result. Microphone headroom is partially a function of the circuit, and partially a function of the capsule.

There are microphones that are designed for higher phantom voltage (DPA has some that use +130V, probably there are others I don't know about), and only in that case would it be appropriate to design a higher voltage supply. However, I would recommend that the voltage be selectable between +48 and +130, as the large majority of microphones are designed for +48.
 
Well, fart. On the phantom side the doubler's not doubling but the xfrmr's spitting out 50VAC. The regulator circuit's not working so I'm only getting 8VDC or so. The +18 is at 17.93 which is OK but I think the -18 regulator's fried because it's stuck on 26V with about 30 going in.

Go figure.
 
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