The K-grade has been obsoleted 10 years ago. No PDN was issued because the test
program for the J-grade and the K-grade are exactly the same. In other words,
the J-grade performance specifications and the K-grade specifications are
exactly the same, only selection of device based on maximum accuracy and
maximum power dissapation (see datasheet grade specs) differeniate between the
J and K grade. Since the J-grade is an exact pin-for-pin, specification
compatible part, there was no need to release an obsolescence notice.
Currently (Feb 2015), we recommend customers use the pin compatible AD9822 (14
bits) or AD9826 (16 bits) instead of AD9814.