what meen “OR” exactly? > do i have to use a other “Sandwitch-PCB” behind the frontpanel when using AIN or AOUT?
The idea is you use:
one Control PCB + one AIN
– OR –
one Control PCB + one AOUT
(you can’t use both in the same “sandwich”)
The Control is flexible in that in can be configured for either; you stuff different resistors/diodes/solder jumpers, while the SIL headers connect to different parts of the respective PCBs.
1 hour ago, Phatline said:
Do i need a Front-PCB @6€ + a AOUT-PCB@6€ to get a 4 AOUT+Trigger-Combi?
Yes. Plus a some sort of DOUT (e.g. SmashTV, MBCV v2).
1 hour ago, Phatline said:
What DAC do you plan > a 4Channel? what type?
MAX525. It is expensive but has proven itself as a good DAC. I soldered two AOUT_NG modules, one doesn’t work and for the other, channel 1 is non-linear viz. my SEQ tuning. I don’t know if that’s a problem with the chip; maybe I overheated it whilst soldering?? But checking on Mouser, MAX525 is one of the cheapest DACs available in DIP. There are a few others, but I couldn’t find many (any?) with serial out (Tx). It’s still listed in active production and if there’s sufficient interest maybe I can look at a bulk order. I’d also like to chat with TK. about a possible MUX/DEMUX board. Thus you might have 32 (64?) inputs for ADC and 32 (64) outputs for DAC using SMP08s, and a 74HC595 to generate chip select addresses.
I like the universal IO board concept you’ve come up with here, well done!
Your choice of using the MAX525 is understandable as its already supported by the MBHP. I assume that you’ve come across mxmxmx’s Ornaments+Crime module? He’s using the TI DAC8565 which has 16 bit precision. I do understand the trade off here of 4 bits for THT but this is worth it in this case.
wow, usually i’m not for smt but i must admit this dac8565 from TI might worth the revisiting,moreover looking @ the price&specs (16bits precision for 15€ @ Mouser)
I see two problems with the DAC8565: no DOUT for serial chaining, and TSSOP is fairly tedious to solder. Those 4 extra bits aren’t too useful considering the error of.. 4 bits!
I’m fine with designing and testing a replacement if one exists!
I’ve come to like working with these type of SMT devices. With a bit of practice I’ve managed to get very good results, indistinguishable from machine placed components.
My “technique” is to solder all the pins not worrying about solder bridges, the main thing being that all the pins are connected to the pads then use desoldering braid to clean up the joints.
This is works every time for me even on TSSOP ICs.
Also If we feel like choosing a new DAC in small package, why not trying to have 8 inputs like AD5676 or MAX5591 , as they are both unexpensive?
Bests,
JK
The adapter PCBs themselves are extremely cheap, the ones I pictured are about £2.95 for 20!
To be honest, I would happily solder a few dozen ICs to these adapters if a bulk buy of the DACs was arranged. They could be sold with the AOUT PCB as a package. Let’s face it, if you are going to by the AOUT board you’re going to have to by the DAC anyway.
The PCB could be redesigned so that a SMT DAC can be soldered directly to the PCB but also has holes to accommodate such an adapter.
DIP/PDIP DACs are almost more expensive and hard to get anyway.
As say Rowan, better face the constraints we will have to face anyway, eg choosing a pretty good unexpensive replacement for MAX525.
And it seems that the right solution to this issue goes through SSOP/TSSOP packages unfortunately.
The idea of the adapter sounds very good to me, because it would allow to use DAC in the traditionals handy DIY-friendly DIP sockets.
Better organize ourselves once the choice is fixed on the DAC to have some presoldered versions on adapters.
(T)SSOP plus an adaptor is a good idea. I’m not sure if pre-soldered products may be sold in Europe(?). I would prefer to keep the chip coupled as closely as possible to the PCB (+1 on the dual use pads), but it looks like time is up on DIP DACs as you say.
Quad vs. Octal: I’d like to keep the quad layout if possible, although it could be doable to have an octal DAC and two quad control panels. If I can avoid re-routing the DAC board too much I’d be happy :).
±0.25 (worst case ±0.75) LSB integral non-linearity
±1 LSB differential non-linearity
3.5mV offset error
6 ppm/C offset-Error Tempco
Typical -0.3 LSB gain error
1 ppm/C gain-Error Tempco
Similar pinout to MAX525
– in fact looks basically like the same die as MAX525
AD5676B:
Octal 16-bit
±1.8 (±3 worst case) LSB integral non-linearity
±0.7 LSB differential non-linearity
?0.75 (worst case ±2) offset error
some other parameters are given as percentages
cost is the same as 2* 5500
chip layout is a clockwise arrangement: a bit annoying to keep the same order (A B C D || H G F E)
not impossible.
MAX5590 B
‘A’ variant is not recommended for new designs… not a good sign
Octal 12-bit
±2 (worst case ±4) LSB integral non-linearity
±1 LSB differential non-linearity
5/25mV offset error
5 ppm/C offset-Error Tempco
±20/±40 LSB gain error(? 2/4?)
1 ppm/C gain-Error Tempco
chip layout is a clockwise arrangement: a bit annoying to keep the same order (A B C D || H G F E)
AD5724RBREZ
Quad 12-bit
±1 LSB integral non-linearity
±1 LSB differential non-linearity
±6mV offset error
4 ppm/C offset-Error Tempco
4 ppm/C gain-Error Tempco
actually a better pin arrangement
expensive
Once the parts arrive I will need to test the MAX525 AOUT to see if the scaling circuit works well in general. Then we could consider an AOUT_3G (?) module.
MAX5500A / AD5676B sounds clearly the 2 best choices.
By my side i’d like to try the AD5676 to see what an octal 16 bits could give, for the experimenting fun.
I like the name “AOUT_3G” . After some breadbord tests , maybe having 2 tests variants could be an idea (dual Quad 12 bits / octal 16 bits).
:to me, MAX5500A sounds the best for your case, eg adapting to an existing routing.
