Updated SSI2130 VCO Datasheet available...

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Re: Updated SSI2130 VCO Datasheet available...

Post by neil.johnson » Fri Jan 15, 2021 10:57 am

adam wrote:
Fri Jan 15, 2021 9:06 am
so, how about that new DAB2130 breakout module then?
Some have shipped to resellers. I tried to call it the "DIPDAB2130" but Dan didn't get the reference.... :doh:

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Re: Updated SSI2130 VCO Datasheet available...

Post by neil.johnson » Fri Jan 15, 2021 11:04 am

Here's one plugged into a Veroboard:
20210115_160043.jpg
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Re: Updated SSI2130 VCO Datasheet available...

Post by adam » Fri Jan 15, 2021 11:26 am

beautiful :)

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Re: Updated SSI2130 VCO Datasheet available...

Post by anotherlin » Sat Jan 16, 2021 5:10 pm

May be I should open a topic for that, but while my SSIs are being shipped, I've already started working on a "submodule" for SSI2131.
It's much like what Electrosmith have done for the 3340. And would have about the same functionnalities, minus the sine wave.
However, it should be a bit lower level as some resistors and maybe buffering opamp would be needed too.

The SSI2130 appears like a very capable VCO IC, probably even better performance wise than the 3340.
It seems to have been designed by Analog Devices former or current R&D engineer (guy named Derek Bowers?).
However, the SSI2131 seems like a better "fit" for a practical VCO. The SSI2130 has just too many features.

The module should be sized like a 40 pins DIP package (for example, PIC18F4550).
I've done the schematic and a draft of placement of the components. Maybe I change the pin assignments to facilitate routing.

Can you guys have a look at the schematic and do a design review?
It's basically the suggested "reference" design from the datasheet.

When possible, I've changed the resistor values (267R to 270R for example) whenever possible to more "common" values.
I've selected 0805 resistor and capacitors with Kicad's "hand-soldering" footprints.

I'll put everything on github when it's done.

The most important thing, when the SSI2131 gonna be available?
surf_green_main.png
surf_green.png
surf_green_power.png
surf_green_io.png

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Re: Updated SSI2130 VCO Datasheet available...

Post by anotherlin » Sat Jan 16, 2021 5:21 pm

A few remarks:

* It uses 78L05 (+5V) and 79L05 (-5) voltage regulators, pretty standard here. In particular, module will be compatible with both +/-15V and +/- 12V.

* It uses the datasheet suggested LM4040C-2.5 reference for Vref.
I've selected the R8 for a little bit more of 1mA available Vref current, which should suffice for "zener current", supply of SS2131, and PWM controller
potentiometer.

* The exponential frequency input(s) will need additional 49.9k resistor(s), with maybe input protection. In fact, hard & soft sync, along FM would
probably need input protection too.

* The outputs (tri, pulse, saw) should be further buffered using TL072.

* The timing capacitor (C1) is on the module with the suggested 3.9nF. Special care must be taken of course for selection (low temp co C0G probably).
Can change footprint to something bigger (1206) if needed.

* PWM control is to use the proposed method of datasheet (hence +5V, -5V, Vref outputs).

* EXPO scale and HF trimming are 10 turns trimpots. They are expensive! EXPO FREQ 0V bias will be single turn (should suffice).

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Re: Updated SSI2130 VCO Datasheet available...

Post by adam » Sun Jan 17, 2021 5:58 am

2131 is coming round the end of next month

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Re: Updated SSI2130 VCO Datasheet available...

Post by tsondie21 » Sun Jan 17, 2021 8:15 pm

I'm getting into this so pardon my ignorance, but I see that there is a 20 microAmp/oct input on pin 7 which can be modified to different current ranges with resistance on the input. What's the difference between 20 microAmp/oct and 1V/oct? I mean, I see that it is current vs. Voltage but I can't find much on why that might be or how one would convert between the two. If I wanted to make a 1V/oct VCO using this part, what would I need to get from a 1V/Oct CV to a corresponding frequency?

EDIT: I think I figured it out just after asking. The 49.9k resistors shown will convert a voltage from 0-10V (0-10 Oct) to the input 0 - 200 microAmp(0-10Oct).

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Re: Updated SSI2130 VCO Datasheet available...

Post by anotherlin » Tue Jan 19, 2021 4:39 am

tsondie21 wrote:
Sun Jan 17, 2021 8:15 pm
EDIT: I think I figured it out just after asking. The 49.9k resistors shown will convert a voltage from 0-10V (0-10 Oct) to the input 0 - 200 microAmp(0-10Oct).
Yes, you're correct. You can even set the sensitivity (uA/oct) by changing the current into EXPO_SCALE (use R = Vref / (4.717 * uA_per_oct)).

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Re: Updated SSI2130 VCO Datasheet available...

Post by neil.johnson » Tue Jan 19, 2021 5:08 am

tsondie21 wrote:
Sun Jan 17, 2021 8:15 pm
I'm getting into this so pardon my ignorance, but I see that there is a 20 microAmp/oct input on pin 7 which can be modified to different current ranges with resistance on the input. What's the difference between 20 microAmp/oct and 1V/oct? I mean, I see that it is current vs. Voltage but I can't find much on why that might be or how one would convert between the two. If I wanted to make a 1V/oct VCO using this part, what would I need to get from a 1V/Oct CV to a corresponding frequency?

EDIT: I think I figured it out just after asking. The 49.9k resistors shown will convert a voltage from 0-10V (0-10 Oct) to the input 0 - 200 microAmp(0-10Oct).
Yes, it is called Ohms Law.

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Re: Updated SSI2130 VCO Datasheet available...

Post by Dogma » Thu Jan 21, 2021 3:59 pm

This is all super exiting :) I’ve been following from afar but it’s time to get dirty...

Is there anyone that has a kit or project for the tzfm/pm wonder chip? 3321 specifically;)

So happy to see these released again, congrats to Neil and all involved!
look up!

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Re: Updated SSI2130 VCO Datasheet available...

Post by neil.johnson » Thu Jan 21, 2021 5:25 pm

Dogma wrote:
Thu Jan 21, 2021 3:59 pm
This is all super exiting :) I’ve been following from afar but it’s time to get dirty...

Is there anyone that has a kit or project for the tzfm/pm wonder chip? 3321 specifically;)

So happy to see these released again, congrats to Neil and all involved!
3321??? Umm do you mean the SSI2131, which doesn't support TZFM/PM, or the SSI2130 which does?

As for kits, the recently announced DAB2130 gets you an SSI2130 on a DIP carrier, much easier to DIY with. You would then need to add the opamps and comparator and bits to make it do TZFM.

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Re: Updated SSI2130 VCO Datasheet available...

Post by Dogma » Fri Jan 22, 2021 2:38 pm

neil.johnson wrote:
Thu Jan 21, 2021 5:25 pm
Dogma wrote:
Thu Jan 21, 2021 3:59 pm
This is all super exiting :) I’ve been following from afar but it’s time to get dirty...

Is there anyone that has a kit or project for the tzfm/pm wonder chip? 3321 specifically;)

So happy to see these released again, congrats to Neil and all involved!
3321??? Umm do you mean the SSI2131, which doesn't support TZFM/PM, or the SSI2130 which does?

As for kits, the recently announced DAB2130 gets you an SSI2130 on a DIP carrier, much easier to DIY with. You would then need to add the opamps and comparator and bits to make it do TZFM.

Neil
Hey Neil - yes I did mean the SSI2131 - I was in a bit of a rush that day, sorry bout that :)

Is the cosmotrinic (sic) - they of the delta-v slope gen, is there upcoming complex osc based on the ssI2131?

So there are no OS diy projects as yet? I’m not at the point where I could build my own circuit but I guess I could try...
look up!

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Re: Updated SSI2130 VCO Datasheet available...

Post by neil.johnson » Fri Jan 22, 2021 5:11 pm

Dogma wrote:
Fri Jan 22, 2021 2:38 pm
Hey Neil - yes I did mean the SSI2131 - I was in a bit of a rush that day, sorry bout that :)
No worries :)
Dogma wrote:
Fri Jan 22, 2021 2:38 pm
Is the cosmotrinic (sic) - they of the delta-v slope gen, is there upcoming complex osc based on the ssI2131?
Sorry I have no idea about that, not even heard of them. The SSI2131 is only just in sampling, so early days.
Dogma wrote:
Fri Jan 22, 2021 2:38 pm
So there are no OS diy projects as yet? I’m not at the point where I could build my own circuit but I guess I could try...
Not to my knowledge. But once the parts are in the main suppliers for DIYers I'm sure there will be a lot of interest!

Cheers
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Re: Updated SSI2130 VCO Datasheet available...

Post by anotherlin » Mon Jan 25, 2021 3:27 pm

Hi everyone,

The SSI2131 module PCB is ready so to speak. It needs to be sent for fabrication (JLCPCB) and it needs of course a SSI2131 for testing it.
It's an open source/free project, so I'll put everything on github when done.
Please have a look at the attached 3D rendering of kicad.
U1 is the SS2131 in SOP16 and the 3 missing SMD parts are 2 multi-turn and 1 single turn trimpots.
It's basically the proposed/reference design from the datasheet. I've changed the pinouts from the schematics published here.

As far as the price of components go, it should be around 20 euros.
The multi-turn trimpots (Bourns 3224) for exponential scale and HF adjustment are pretty expensive, around 3.2 euros.
The single-turn trimpot (Bourns) for 0V CV bias, is about 1.2 euros.
The price of the SSI2131 is yet to be known, however the SSI2130 is around 6.75 euros.
Other parts (resistors, capacitors, voltage regulator and reference) are standard/common, hence very cheap.

Now I need to get hand at an SSI2131 chip!

In the meantime, I need to design an eurorack module that use it.
It will basically like the 3340 VCO from Electro-Smith, minus the sinus wave output.


Best regards,
surf_green_module.png

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Re: Updated SSI2130 VCO Datasheet available...

Post by neil.johnson » Tue Jan 26, 2021 12:51 pm

anotherlin wrote:
Mon Jan 25, 2021 3:27 pm
The SSI2131 module PCB is ready so to speak. It needs to be sent for fabrication (JLCPCB) and it needs of course a SSI2131 for testing it.
It's an open source/free project, so I'll put everything on github when done.
Please have a look at the attached 3D rendering of kicad.
U1 is the SS2131 in SOP16 and the 3 missing SMD parts are 2 multi-turn and 1 single turn trimpots.
It's basically the proposed/reference design from the datasheet. I've changed the pinouts from the schematics published here.
Even so, a schematic would help.
anotherlin wrote:
Mon Jan 25, 2021 3:27 pm
Now I need to get hand at an SSI2131 chip!
A little bird tells me sometime in February, but with CNY coming up it will either be early Feb or the very end.

Neil
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Re: Updated SSI2130 VCO Datasheet available...

Post by anotherlin » Tue Jan 26, 2021 5:03 pm

neil.johnson wrote:
Tue Jan 26, 2021 12:51 pm
Even so, a schematic would help.
It's just the schematics published just a few messages before, on Sunday 17th January.
I've updated the pinouts. See attached pdf for full schematics. Feel free to give some comments or suggestions :)

I should write a BOM and small description of the module.
Prepare a symbol and footprint for the said module.
And also a small eurorack as a reference design for module use.

I'll try my luck sending an email to Sound Semiconductor for 1-2 SSI2131 sample.
Hope they're friendly :)

It would be great if they (soundsemi) offer an even simpler version of the SSI2131 but with sinewave for LFO purpose.

surf_green.pdf
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Re: Updated SSI2130 VCO Datasheet available...

Post by adam » Tue Jan 26, 2021 5:24 pm

you can always make your own sine shaper

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Re: Updated SSI2130 VCO Datasheet available...

Post by anotherlin » Tue Jan 26, 2021 5:36 pm

adam wrote:
Tue Jan 26, 2021 5:24 pm
you can always make your own sine shaper
But a ready to use LFO IC is even more handier :)

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Re: Updated SSI2130 VCO Datasheet available...

Post by adam » Tue Jan 26, 2021 5:38 pm

changing the value of the timing cap should allow usage as an LFO

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Re: Updated SSI2130 VCO Datasheet available...

Post by neil.johnson » Wed Jan 27, 2021 4:16 am

anotherlin wrote:
Tue Jan 26, 2021 5:36 pm
adam wrote:
Tue Jan 26, 2021 5:24 pm
you can always make your own sine shaper
But a ready to use LFO IC is even more handier :)
Yes indeed! It's called the SSI2130 :yay:

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Re: Updated SSI2130 VCO Datasheet available...

Post by kybernetik » Thu Jan 28, 2021 5:24 am

Stab Frenzy wrote:
Wed Dec 09, 2020 2:20 am
I've run into a peculiar quirk when testing my prototype on a variety of Eurorack power supplies. I have one supply where the -12V rail comes up around 8ms after the +12V, using this supply the 2130 locks up with the voltage on tcap at around 3.5V. I'm not using the Strobe pin in this design so it's not broken out, otherwise I'd see if I could reset it after both rails were up. The 2130 is supplied by +5V and -5V regulators, the -5V rail floats at around +0.7V until the -12V rail is up.

Any thoughts on what's going on internally and how it might be avoided? This situation isn't that unlikely in the wild west of Eurorack power so I'd like to design the module in a way that can tolerate it on startup.
I've encountered the exact same issue, anyone else?

Is there a possible solution for this?
- Cosmotronic -

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Re: Updated SSI2130 VCO Datasheet available...

Post by neil.johnson » Thu Jan 28, 2021 6:02 am

kybernetik wrote:
Thu Jan 28, 2021 5:24 am
Stab Frenzy wrote:
Wed Dec 09, 2020 2:20 am
I've run into a peculiar quirk when testing my prototype on a variety of Eurorack power supplies. I have one supply where the -12V rail comes up around 8ms after the +12V, using this supply the 2130 locks up with the voltage on tcap at around 3.5V. I'm not using the Strobe pin in this design so it's not broken out, otherwise I'd see if I could reset it after both rails were up. The 2130 is supplied by +5V and -5V regulators, the -5V rail floats at around +0.7V until the -12V rail is up.

Any thoughts on what's going on internally and how it might be avoided? This situation isn't that unlikely in the wild west of Eurorack power so I'd like to design the module in a way that can tolerate it on startup.
I've encountered the exact same issue, anyone else?

Is there a possible solution for this?
First thing, the STROBE pin needs to be pulled low for the oscillator to run. If left unconnected it will float high and stop the oscillator.

Secondly, how are you connecting the unused mix control pins? If you are not using them please leave them unconnected. Same with the bottom pad, which should be unconnected.

Can you provide some scope shots of the two power rails at the SSI2130? Also the current draw on the +5V and -5V rails.

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Re: Updated SSI2130 VCO Datasheet available...

Post by kybernetik » Thu Jan 28, 2021 7:33 am

neil.johnson wrote:
Thu Jan 28, 2021 6:02 am
Secondly, how are you connecting the unused mix control pins? If you are not using them please leave them unconnected. Same with the bottom pad, which should be unconnected.
Ok that might have something to do with it, I'll fix it and let you know if that solves it. I'm not in the lab at the moment, but I'll try it as soon as possible. Thanks Neil!
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Re: Updated SSI2130 VCO Datasheet available...

Post by Rengel » Sun Jan 31, 2021 4:25 pm

Hello,

getting a headache to thinking of soldering the IC into a pcb, I though it would be good to have it on a module:
- if the circuit does not work, it would be possible to remove the SSI and use it somewhere else (e.g. a corrected pcb).
- if the SSI dies because I did something wrong I could simply remove the module without roasting all the circuitry around.
Then I thought - OK if I already have the pain to do SMD soldering, then I can also put a reference and the linear regulators etc on the module - and then I could also reduce the number of pins and use a DIP24 socket.
Here is what it looks like:
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Re: Updated SSI2130 VCO Datasheet available...

Post by neil.johnson » Sun Jan 31, 2021 4:35 pm

Rengel wrote:
Sun Jan 31, 2021 4:25 pm
Hello,

getting a headache to thinking of soldering the IC into a pcb, I though it would be good to have it on a module:
- if the circuit does not work, it would be possible to remove the SSI and use it somewhere else (e.g. a corrected pcb).
- if the SSI dies because I did something wrong I could simply remove the module without roasting all the circuitry around.
Then I thought - OK if I already have the pain to do SMD soldering, then I can also put a reference and the linear regulators etc on the module - and then I could also reduce the number of pins and use a DIP24 socket.
Here is what it looks like:
Hi, and welcome. Looks great - did you get the PCB fab to populate the board for you, or did you do it yourself? Looks very neat.
I hope you did not connect the bottom pad to ground...?

Cheers
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