CONDENSED CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2011	Jan. 01, 2011	Dec. 31, 2011	Jan. 01, 2011
CONDENSED CONSOLIDATED STATEMENTS OF INCOME [Abstract]
Net sales	$ 14,066	$ 19,675	$ 49,084	$ 65,189
Cost of sales	8,708	9,341	26,132	29,121
Gross profit	5,358	10,334	22,952	36,068
Research and development	3,480	3,692	10,514	10,823
Selling, general and administrative	3,269	3,501	9,226	10,673
Total operating expenses	6,749	7,193	19,740	21,496
(Loss) income from operations	(1,391)	3,141	3,212	14,572
Interest income	251	172	737	589
Other income (expense), net	533	273	(170)	490
(Loss) income before provision for income taxes	(607)	3,586	3,779	15,651
(Benefit from) provision for income taxes	(703)	726	303	4,861
Net income	$ 96	$ 2,860	$ 3,476	$ 10,790
Net income per share
Basic	$ 0.01	$ 0.22	$ 0.28	$ 0.83
Diluted	$ 0.01	$ 0.22	$ 0.28	$ 0.83
Shares used in per share computation:
Basic	12,063	13,036	12,439	12,995
Diluted	12,066	13,079	12,450	13,054