Dallas-based Texas Instruments (NASDAQ:TXN) is narrowing guidance on what it expects to earn in its fiscal third quarter 2013 -- the quarter we're currently in, and which closes on Sept. 30.

Announcing tweaks to its projected numbers, TI compressed the ranges of both the revenues and the earnings that it expects to report -- originally announced in the company's July 22 fiscal Q2 2013 earnings release. Instead of a range of from $3.09 billion to $3.35 billion, TI now sees a higher "floor" revenue -- $3.15 billion -- but also a lower "ceiling" on the revenue it might report: $3.29 billion.

Similarly, the company's earnings estimate of from $0.49 to $0.57 has changed. The worst-case scenario is now $0.51 per share; the best case, $0.55 per share.

Texas Instruments investors appear to be accenting the negative side of the update, with TI shares opening down from yesterday's $40.31 close, and trading close to that closing price as of this writing. Official earnings are expected to be released on Oct. 21.