Il gallo, part3 plan for layout

I did some layout work for "Il gallo super quiet amplifier OOOHHHH"

Waiting for this box

Plan is to use "50x25x25mm Aluminum PCB Instrument Box Electronic Cooling Enclosure Case"
Its quite small , actually maybe too small. I realized that I am not able to put two 4 pin JST connectors on short side..  4pin + 2pin goes ok.

Ok... thinking out of box... installing PCB diagonally would be also possible :D :D

So plan is to have

• On front: 4pin SPI connector and 2pin (3.3v,gnd)
• On Back  2pin current input  and 2pin power supply (+12v GND)

On inside. I reserverd connectors for

• reset and rdy pins for ADC (not really needed)
• Analog connector for analog use (possible to provide external +2.5, gnd, -2.5v)

Il gallo, freezed before recieving enclosure

And here is layout

Layout allows to use LTC6268 (one amplifier) or LTC6269 (two amplifiers in cascade). Depends about how much money I have for spare for hobby.

I realized also how JST connector can be installed as SMD. No need for corner model. 

JST connector stays on foil.. even when using force..

I prototyped and foud out that even two pin model stays in place and copper foil is not rising.

The bad thing is that this installation style requires hand soldering...so it is not ok for mass production. For hobbyist kits it is ok (expecially when board allows multiple installation styles)

I created footprint with both.. hole and SMD pad. Holes are for "normal" installation. In case where other side of JST connector is soldered on BNC connector or something like that.  I try avoid expensive coaxial cables and connectors as long as I can :)

I put this design on hold while some parts are arriving. DRC is passing  now :)

But hurrying with pcb order would be stupid. I go suidical very easilly..if I do mistakes.. (expecially if I pay for pcbs and there is fail).. But don't worry suidical attitude is just normal at Finland. It is like slavic mentality but not so happy. Slavs drink more vodka and use krokodil-drug... (I dont do drugs because I am not slav, beer is enough for me)

 I do first mechanical mockup.. and maybe electrical mockup (ADC can be issue.. AD7705 says that it have buffer... but is driving ADC thru divider bad idea?)

For now... I have used too much spare time for Il gallo.. I will do something else for next monday. Maybe software?