Condensed Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 29, 2013	Jun. 30, 2012	Jun. 29, 2013	Jun. 30, 2012
Income Statement [Abstract]
Net sales	$ 213,725	$ 196,383	$ 596,985	$ 580,434
Cost of sales	130,461	116,138	359,755	342,182
Gross profit	83,264	80,245	237,230	238,252
Operating expenses:
Research and development	21,782	19,306	61,229	58,408
Selling, general and administrative	38,748	32,894	113,076	102,902
Amortization of intangible assets	1,290	1,723	4,086	4,970
Total operating expenses	61,820	53,923	178,391	166,280
Income from operations	21,444	26,322	58,839	71,972
Other income (expense):
Interest and dividend income	48	52	161	283
Interest expense	(37)	(71)	(60)	(78)
Other—net	(964)	(1,918)	(1,196)	288
Total other income (expense), net	(953)	(1,937)	(1,095)	493
Income before income taxes	20,491	24,385	57,744	72,465
Provision for income taxes	3,806	7,177	11,904	22,051
Net income	$ 16,685	$ 17,208	$ 45,840	$ 50,414
Net income per share:
Basic	$ 0.69	$ 0.73	$ 1.91	$ 2.14
Diluted	$ 0.68	$ 0.72	$ 1.87	$ 2.10
Shares used in computation:
Basic	24,310	23,633	24,055	23,538
Diluted	24,690	24,054	24,462	24,004