CONDENSED CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Jun. 29, 2013	Jun. 30, 2012
CONDENSED CONSOLIDATED STATEMENTS OF INCOME [Abstract]
Net sales	$ 16,198	$ 16,059
Cost of sales	7,466	8,565
Gross profit	8,732	7,494
Research and development	3,480	3,486
Selling, general and administrative	3,149	3,384
Total operating expenses	6,629	6,870
Income from operations	2,103	624
Interest income	409	301
Other income (expense), net	60	(99)
Income before provision for income taxes	2,572	826
(Benefit from) provision for income taxes	(314)	229
Net income	$ 2,886	$ 597
Net income per share
Basic	$ 0.25	$ 0.05
Diluted	$ 0.25	$ 0.05
Shares used in per share computation:
Basic	11,528,000	11,999,000
Diluted	11,585,000	12,001,000