CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2012	Apr. 02, 2011	Apr. 03, 2010
CONSOLIDATED STATEMENTS OF INCOME [Abstract]
Net sales	$ 65,535	$ 83,172	$ 66,724
Cost and expenses:
Cost of sales	34,855	37,984	34,722
Research and development	14,399	14,851	15,404
Selling, general and administrative	12,840	14,194	12,840
Total costs and expenses	62,094	67,029	62,966
Income from operations	3,441	16,143	3,758
Interest and other income:
Interest income	999	812	1,058
Other income, net	405	825	1,560
Income before provision for income taxes	4,845	17,780	6,376
Provision for income taxes	96	5,498	1,251
Net income	$ 4,749	$ 12,282	$ 5,125
Net income per share
Basic (in dollars per share)	$ 0.38	$ 0.95	$ 0.40
Diluted (in dollars per share)	$ 0.38	$ 0.94	$ 0.39
Shares used in per share computation
Basic (in shares)	12,340	12,976	12,912
Diluted (in shares)	12,351	13,030	12,995