Segment Information - Revenue by Product Line (Details) - USD ($)	3 Months Ended
Apr. 28, 2019	Apr. 29, 2018
Revenue from External Customer [Line Items]
Net sales	$ 131,354,000	$ 130,429,000
Signal Integrity
Revenue from External Customer [Line Items]
Net sales	50,257,000	65,599,000
Protection
Revenue from External Customer [Line Items]
Net sales	38,890,000	40,792,000
Wireless and Sensing
Revenue from External Customer [Line Items]
Net sales	42,207,000	45,539,000
Other: Warrant Shares
Revenue from External Customer [Line Items]
Net sales offset	$ 0	$ (21,501,000)
Net sales
Revenue from External Customer [Line Items]
Concentration risk, percentage	100.00%	100.00%
Net sales \| Signal Integrity
Revenue from External Customer [Line Items]
Concentration risk, percentage	38.00%	50.00%
Net sales \| Protection
Revenue from External Customer [Line Items]
Concentration risk, percentage	30.00%	31.00%
Net sales \| Wireless and Sensing
Revenue from External Customer [Line Items]
Concentration risk, percentage	32.00%	35.00%
Net sales \| Other: Warrant Shares
Revenue from External Customer [Line Items]
Concentration risk, percentage	0.00%	(16.00%)

Allocated share-based compensation expense as a percentage of net revenue

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- Definition

Revenue Offset

+ References

No definition available.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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