I think the best bet for answering this question will be a community wiki, in which we post what we know for several different L1/L2 orbiters. I'll start.
L1 - the fastest I know:
LISA Pathfinder was launched on the 3rd of December 2015 and reached L1 orbit on the 22nd of January 2016. So that's 50 days.
L1 - other:
SOHO (Solar and Heliospheric ...
The Deep Impact spacecraft's impactor, matching Tempel 1's inclination of 10.47 degrees upon collision.
The Dawn spacecraft, matching Ceres' inclination of 10.59 degrees.
The NEAR Shoemaker spacecraft, matching 433 Eros' inclination of 10.83 degrees upon landing.
Solar Orbiter is currently beating all of them, at ~14 degrees.
The very first analog to digital conversion was used in the first satellite ever: Sputnik 1. A barometric switch was used to signal if the gas pressure inside dropped below 130 kPa. A mechanical analog to digital converter with only one bit. I never saw a definition that an ADC should have at least 2, 3 or 4 bits.
There were two thermal switches for ...
The first analog to digital converter was flown on board Injun 1 on June 29, 1961. It was also the first spacecraft completely designed and built by a university--in this case, the University of Iowa.
From "The Origins of Space Radio and Plasma Wave Research at the University of Iowa" by Donald A. Gurnett:
At the suggestion of a newly hired Assistant ...