Chip maker INTERSIL announced it plans to buy ELANTEC semiconductor for $1.4 billion. It's a move by the company to expand into a fast-growing analog market. According to the terms of the agreement, each share of ELANTEC's shareholders can be exchanged for 1.24 shares of INTERSIL and $8 in cash. According to Friday's closing price, ELANTEC's shares are valued at $53.45 a share, with a premium rate of nearly 30%.