Re: [ARTIQ] ARTIQ hardware proposal

2016-03-19 Thread Tan, Ting Rei (IntlAssoc) 
I agree that not stuffing ADC does not make things worthwhile. How about 
considering a DSP breakout board similar to the standalone digital box? This, 
obviously, is another piece of hardware need to be maintained. But I think this 
makes more sense for the application of laser stabilization, i.e. you want the 
servo controller physically closer to your laser system rather than have all of 
them sitting inside a crate. 

I am not very clear about the analog FMC card (item 6) as it is not indicated 
in the 'system overview' diagram. Is this basically a DSP breakout board? 

Also, how about considering a 2:1 DAC to ADC channels ratio for DSP? I think 
most experiments prefer more output than input. 

Ting Rei

-Original Message-
From: Robert Jördens [mailto:jord...@gmail.com] 
Sent: Saturday, March 19, 2016 3:10 PM
To: Tan, Ting Rei (IntlAssoc) 
Cc: artiq@lists.m-labs.hk
Subject: Re: [ARTIQ] ARTIQ hardware proposal

On Sat, Mar 19, 2016 at 8:54 PM, Tan, Ting Rei (IntlAssoc) 
 wrote:
> For complicated trap users, the most common use case is to drive trap 
> electrode so we will need much more DAC channels and ADC channels. One 
> possible solution is to have two kind of DSP boards? One with balanced 
> DAC and ADC channels and the other with only DAC.

Specifying, designing, producing, stocking, and selling more boards just to get 
variations is quite time consuming and expensive. Two things to consider here:
We can probably do a run where the ADCs are not populated. But you won't get 
more DAC channels and the amount of money saved might not make it worth the 
trouble. Also for "many DAC channels" we will probably end up needing to do 
hardware anyway.

--
Robert Jordens.
___
ARTIQ mailing list
https://ssl.serverraum.org/lists/listinfo/artiq

Re: [ARTIQ] ARTIQ hardware proposal

2016-03-19 Thread Robert Jördens 
On Sat, Mar 19, 2016 at 8:54 PM, Tan, Ting Rei (IntlAssoc)
 wrote:
> For complicated trap users, the most common use case is to drive trap
> electrode so we will need much more DAC channels and ADC channels. One
> possible solution is to have two kind of DSP boards? One with balanced DAC
> and ADC channels and the other with only DAC.

Specifying, designing, producing, stocking, and selling more boards
just to get variations is quite time consuming and expensive. Two
things to consider here:
We can probably do a run where the ADCs are not populated. But you
won't get more DAC channels and the amount of money saved might not
make it worth the trouble. Also for "many DAC channels" we will
probably end up needing to do hardware anyway.

--
Robert Jordens.
___
ARTIQ mailing list
https://ssl.serverraum.org/lists/listinfo/artiq

Re: [ARTIQ] ARTIQ hardware proposal

2016-03-19 Thread Robert Jördens 
On Sat, Mar 19, 2016 at 12:09 PM, Sébastien Bourdeauducq  wrote:
> What about grounding the FMC pins near the analog signals, would that help?

Yes. This is also what the USRP hardware does. And FMC does ground
shielding for its regular digital pairs as well. Given that nobody
seems to have done analog over the FMC connector, it would be useful
to measure the pair-to-pair coupling on a FMC prototype board and then
alternatively (and in any case if RFI requires caging) use separate
shielded connectors. It wouldn't be too ugly because mounting an FMC
already needs more than just fingers.

Robert.
___
ARTIQ mailing list
https://ssl.serverraum.org/lists/listinfo/artiq

Re: [ARTIQ] ARTIQ hardware proposal

2016-03-19 Thread Sébastien Bourdeauducq 
On Friday, 18 March 2016 4:27:53 PM HKT Ben Keitch wrote:
> This gives me a 404:
> 
> http://ssl.serverraum.org/lists-archive/artiq/attachments/20160318/ce9d656c/
> attachment.pdf

This links works fine here. Anyway, here is the slightly updated version. 
Change log: https://github.com/m-labs/artiq-hardware

Sébastien


artiq_hardware.pdf
Description: Adobe PDF document
___
ARTIQ mailing list
https://ssl.serverraum.org/lists/listinfo/artiq