The Texas Instruments SN74LVC1G126DCKJ is a single-bit, non-inverting buffer with a 3-state output, part of the 74LVC low-voltage CMOS logic family.
That means TI no longer manufactures this specific package variant (SC-70-5, Tape & Reel). For a BOM line that must be filled, the options are to buy remaining stock through independent distribution or to migrate to a current-production alternate. If your board accepts the SC-70-5 footprint, the DCKR is a drop-in replacement. No official TI successor beyond the DCKR variant has been published for this order code.
Date-code and marking check for gray-market stock
Because this part is obsolete, any stock you find on the open market may be several years old. The top-side marking is typically a three-character code — check that the laser etch matches TI's known marking scheme for the 74LVC1G126 in SC-70-5. Date codes should be consistent within a reel; a mix of date codes from different production years on the same tape is a red flag. If the parts are from a broker rather than an authorized TI distributor, a decap and X-ray inspection can confirm the die matches the 74LVC1G126 mask set. The SC-70-5 package is small and easily counterfeited with a re-marked generic buffer die, so provenance matters.