Can't identify HT74 Texas Instruments smd chip
The ordering information table on page 1 shows two pacakges that have the "HT74" topmark, SSOP "DB" and TSSOP "PW". The "PW" comes in different size tape/reel, but since you'll probably just be buying a single unit from digikey or mouser all you really need is the DB or PW suffix.

TI's "DB" package and their "PW" package are both plastic small-outline with 0.65mm pitch, but the key difference is the width of the body (i.e. the width of the black epoxy encapsulation between the two rows of pins; 5.6mm for DB package; 4.5mm for PW package). It's possible that the PCB footprint might be wide enough to accommodate either package. You need to measure this to determine which package your chip has. The package outline drawings are towards the end of the datasheet. Page 11 is the "DB" package outline drawing, page 18 is the "PW" package outline drawing. Note that these package outlines sometimes support a whole family of similar package styles, so even though the "DB" drawing says 28 pins it really applies to the 14 pin DB package as well.

You can safely ignore the "66KG4CGKT" lot tracking code, there's no way to order a specific lot number. That's just a tracking number that QA can use if there is a problem.