Question on BBD chips

haspelman · September 30, 2004, 02:47:49 PM

Hi!

Are there any differences between the MN320x and the MN300x BBDs? The 320x are much cheaper than the 300x. Are they pin compatible to each other? I mean for example, can I replace a MN3007 by a MN3207 without any changes in the schematic?

The clock driver MN3101 and MN3102, does it matter which one to use?

Thank you for your help!

Haspel

bioroids · September 30, 2004, 02:54:25 PM

They are not pin-compatible, and they have some other differences, in special the voltage supply the can use, the headroom they have and etc..

Check out the datasheets (they can be found at Mark Hammer's site)

Anyway you can adapt the circuits to use them, but is not that simple
(at least it took me several weeks to make a zombie chorus using a mn3207, and the results weren't very good), there is more than just changing the paths to the correct pins

But it can be done, and the chips are a lot cheaper in fact

Luck!

Miguel

Thomas P. · September 30, 2004, 03:45:36 PM

MN3101 is to drive MN300x
MN3102 is to drive MN320x

The MN300x are designed for -15VDD
The MN320x for +5VDD

Mark Hammer · September 30, 2004, 03:48:36 PM

If you spend a bt of time looking over the datasheets, you'll see the following pattern emerge:

1) 33xx chips have more relaxed requirements for supply voltage than 32xx, and 32xx more relaxed requirements than 30xx.

2) Those chips using a lower supply voltage can be clocked faster than chips with identical stage-capacity but higher supply voltages. So, you can clock an MN3307 faster than an MN3207, and an MN3207 faster than an MN3007. Bear in mind this is completely with respect to a MN3xxx clock chip driving the BBD directly, and NOT with respect to other things one can do to help the BBD clock at a faster speed.

3) The S/N ratios generally tend to be better for higher supply voltage chips (MN30xx > MN32xx > MN33xx).

Bottom line? If battery life/requirements is not an issue, and neither is board footprint or production costs, the MN30xx chip is probably the one to use for any given storage capacity. You can always get more current/voltage form the wall, and you can always figure out a way to get the chip to clock faster if you need ultrashort delay times for some reason, but it's hard to recover noise-free headroom you never had.

Reality check: Differences between the chip series with respect to noise are small, though meaningful. Bear in mind, though, that S/N specs are established using steady-state tones; something you will very rarely, if ever feed yor delay-based projects. In the vast majority of instances, your input signal will be well below that needed to attain the noise specs shown on the datasheets. Indeed, the filtering and/or companding scheme used in the design will have several orders of magnitude more impact on the noise of the effect than will chip series differences.

Second bottom line? Get what's cheap and easy to work with.

Vsat · September 30, 2004, 04:13:28 PM

Also keep in mind that operating the MN32xx series near the top of it's recommended supply voltage range will provide S/N similar to MN30xx operated near the lower end of it's supply range ( I prefer to operate MN32xx at 9 volts, don't go much above this or you'll exceed the abs. max supply rating. They can be operated at 5 volts or lower if necessary).

Another point to keep in mind is the fewer the BBD stages, the better the S/N... the MN3006 with 128 stages has significantly better S/N than the MN3007. Higher clock rate also helps the S/N...
Regards, Mike

cd · September 30, 2004, 05:19:33 PM

Can a 3102 be used to drive a 3007?

puretube · September 30, 2004, 05:25:24 PM

answer: in 3rd post...

cd · September 30, 2004, 05:33:24 PM

Quote from: puretubeanswer: in 3rd post...

Heh, I read that

Perhaps I should have been more specific - 3102 is designed for 3207, 3101 for 3007. Can a 3102 be used ona 3007 (or a 3101 on a 3207), or are the requirements totally different so as to be incompatible?

puretube · September 30, 2004, 05:36:04 PM

reversed supply polarities... :cry:

(it "can" be done, however, of course...)

[like a FF with neg. GND]

Fret Wire · September 30, 2004, 11:39:49 PM

If you were going to update a ckt layout that originally had a SAD512D (dip 8-pin), what would be the nearest work-alike, a MN3204? MN3004?

Nick123 · October 01, 2004, 03:35:17 AM

MN3004 because off higher supply voltage than
MN3204. MN3004 has much higher S/N ratio than
SAD512D as well.
TDA1022 is a good replacement too.

puretube · October 01, 2004, 03:41:22 AM

"workalikes" concerning number of stages (512) would be:

MN3002 (DIP14);
MN3004 (DIP14);
MN3204 (DIP8 );
MN3304 (DIP8 );

TDA1022 (DIP16);

be sure to check out the different (dual) clock requirements and supply
polarities!

Thomas P. · October 01, 2004, 04:46:12 AM

About the TDA1022:
I've posted an application corcuit and a clock driver for it from an old (erly 80s) electronics magazin (elrad). Just if someone's courious :wink:

puretube · October 01, 2004, 04:52:50 AM

tomboy: did you try to get tda1022 from "Reichelt", lately?

Thomas P. · October 01, 2004, 05:05:14 AM

Quote from: puretubetomboy: did you try to get tda1022 from "Reichelt", lately?

I will!!!!! Why is it sold out (fingers crossed)!

puretube · October 01, 2004, 05:11:33 AM

well, it was sold out last year...

Thomas P. · October 01, 2004, 05:18:26 AM

Quote from: puretubewell, it was sold out last year...

I ordered a few right now - maybe they've found another box of them under the roof :wink:

Fret Wire · October 01, 2004, 10:46:33 AM

QuoteMN3004 because off higher supply voltage than
MN3204. MN3004 has much higher S/N ratio than
SAD512D as well.
TDA1022 is a good replacement too.

Quote"workalikes" concerning number of stages (512) would be:

MN3002 (DIP14);
MN3004 (DIP14);
MN3204 (DIP8 );
MN3304 (DIP8 );

TDA1022 (DIP16);

be sure to check out the different (dual) clock requirements and supply
polarities!

Thanks guys. I was thinking about MXR's Micro Chorus and Micro Flanger, both of which use the SAD512D.

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Question on BBD chips