CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 01, 2017	Apr. 02, 2016	Apr. 01, 2017	Apr. 02, 2016
Income Statement [Abstract]
Net revenue	$ 199,613	$ 156,400	$ 349,252	$ 264,934
Cost of sales	109,322	86,753	190,643	144,866
Gross profit	90,291	69,647	158,609	120,068
Selling, general and administrative	32,666	35,499	62,198	63,431
Research and development	25,020	22,439	46,525	46,633
Operating expenses	57,686	57,938	108,723	110,064
Income from operations	32,605	11,709	49,886	10,004
Interest income	1,579	701	2,751	1,323
Interest expense	(261)	(276)	(523)	(549)
Income before income taxes	33,923	12,134	52,114	10,778
Income tax expense	4,882	7,045	7,490	5,780
Net income	$ 29,041	$ 5,089	$ 44,624	$ 4,998
Net income per share:
Basic (in dollars per share)	$ 0.41	$ 0.07	$ 0.63	$ 0.07
Diluted (in dollars per share)	$ 0.40	$ 0.07	$ 0.62	$ 0.07
Weighted average shares outstanding:
Basic (in shares)	70,964	70,389	70,909	70,563
Diluted (in shares)	72,270	70,634	72,039	70,801