Segment Information - Revenue by Product Line (Details) - USD ($) $ in Thousands	3 Months Ended
	May. 01, 2016	Apr. 26, 2015
Revenue from External Customer [Line Items]
Net sales	$ 131,145	$ 130,088
Signal Integrity [Member]
Revenue from External Customer [Line Items]
Net sales	69,882	54,309
Protection [Member]
Revenue from External Customer [Line Items]
Net sales	31,570	37,127
Wireless and Sensing [Member]
Revenue from External Customer [Line Items]
Net sales	15,607	22,798
Power and High Reliability [Member]
Revenue from External Customer [Line Items]
Net sales	13,881	14,013
Systems Innovation [Member]
Revenue from External Customer [Line Items]
Net sales	$ 205	$ 1,841
Net sales [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage	100.00%	100.00%
Net sales [Member] | Signal Integrity [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage	53.00%	41.00%
Net sales [Member] | Protection [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage	24.00%	29.00%
Net sales [Member] | Wireless and Sensing [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage	12.00%	18.00%
Net sales [Member] | Power and High Reliability [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage	11.00%	11.00%
Net sales [Member] | Systems Innovation [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage	0.00%	1.00%