[time-nuts] DAC performance [WAS: Papers on timing for lunar laser ranging]

[Attila Kinali]

On Sun, 16 Jul 2017 14:24:24 -0400
Charles Steinmetz <csteinmetz at yandex.com> wrote:


> Well, to name just the first one that comes to mind, how about the 
> LTC1650?  Like the 1655, it is available in SO and DIP packages.  Its 
> differential nonlinearity is >2x better than the 1655, it settles 5x 
> faster (4uS vs. 20uS to 1 LSB) and is nearly 100x (40dB) quieter 
> (30nV/sqrtHz vs. 280).  The 1650 has substantially lower glitch energy, 
> as well (1.8nV-S for the 1650, 12nV-S for the 1655).

I was about to ask the same question :-)

BTW: I am planning to do something similar with an LT1650 and
thought about adding an CMOS switch to minimize the glitch energy.
Though even low charge injection switches like the ADG5212/5213
give something in the order of 0.5pC.. which turns out to be in the
order of magnitude of the LTC1650's worst case glitch energy, if put
into a complete circuit.

I am sure there are ways to compensate for the charge injection
by using multiple switches, but I have not been able to come up
with a good way. Does anyone have a good idea?

> I have not surveyed the field to see what other "SO or easier to solder" 
> DACs are available with better performance than the 1655, but I'm sure 
> there are others.

There is also the AD5060 family from Analog. Though their performance
is slightly worse then the LTC1650, they are much cheaper. Unless you
need the high specs, they are a cheap alternative.
 
			Attila Kinali

-- 
You know, the very powerful and the very stupid have one thing in common.
They don't alters their views to fit the facts, they alter the facts to
fit the views, which can be uncomfortable if you happen to be one of the
facts that needs altering.  -- The Doctor