Geographic Information and Concentration of Risk - Net Sales Activity by Product Line (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jan. 27, 2013	Oct. 28, 2012	Jul. 29, 2012	Apr. 29, 2012	Jan. 29, 2012	Oct. 30, 2011	Jul. 31, 2011	May 01, 2011	Jan. 27, 2013	Jan. 29, 2012	Jan. 30, 2011
Product Information [Line Items]
Net sales	$ 150,603	$ 160,878	$ 150,704	$ 116,642	$ 104,032	$ 123,944	$ 130,254	$ 122,371	$ 578,827	$ 480,601	$ 454,502
Advanced Communications
Product Information [Line Items]
Net sales									133,533	139,695	112,019
Concentration risk, percentage									23.00%	29.00%	25.00%
Wireless and Sensing
Product Information [Line Items]
Net sales									50,444	57,124	59,107
Concentration risk, percentage									9.00%	12.00%	13.00%
Power Management and High Reliability
Product Information [Line Items]
Net sales									66,427	74,056	87,693
Concentration risk, percentage									12.00%	15.00%	19.00%
Protection
Product Information [Line Items]
Net sales									198,866	209,726	195,683
Concentration risk, percentage									34.00%	44.00%	43.00%
Gennum
Product Information [Line Items]
Net sales									$ 129,557	$ 0	$ 0
Concentration risk, percentage									22.00%	0.00%	0.00%