

(in thousands)	Signal Integrity		Wireless and Sensing		Protection		Total
Balance at January 27, 2019	$	274,085	$	72,128	$	4,928	$	351,141
Additions	—		—		—		—
Balance at October 27, 2019	$	274,085	$	72,128	$	4,928	$	351,141



(in thousands)	Signal Integrity		Wireless and Sensing		Protection		Total
Balance at January 28, 2018	$	274,085	$	67,812	$	—	$	341,897
Additions ^{(1) (2)}	—		8,500		4,778		13,278
Balance at October 28, 2018	$	274,085	$	76,312	$	4,778	$	355,175

⁽¹⁾ On August 17, 2018, the Company, through its subsidiary Semtech (International) AG, a Swiss corporation, entered into the TrackNet Acquisition for approximately $8.5 million, with the entire purchase price preliminarily attributed to goodwill as of October 28, 2018. During the fourth quarter of fiscal year 2019, the Company finalized the purchase price allocation for the TrackNet Acquisition, which resulted in $4.3 million of the purchase price attributed to goodwill.

⁽²⁾ On May 2, 2018, the Company acquired substantially all of the assets of ICI for an aggregate purchase price of approximately $7.4 million, of which $4.8 million was preliminarily attributed to goodwill as of October 28, 2018. During the fourth quarter of fiscal year 2019, the Company finalized the purchase price allocation for the acquisition of ICI, which resulted in $4.9 million of the purchase price attributed to goodwill.

The reporting units are the same as the operating segments, which are part of a single reportable segment (see Note 13).

Goodwill is tested for impairment at the reporting unit level during the fourth quarter of each fiscal year. In addition to its annual review, the Company performs a test of impairment when indicators of impairment are present. As of October 27, 2019, there was no indication of impairment of the Company's goodwill balances.

The following table sets forth the Company’s finite-lived intangible assets resulting from business acquisitions, which continue to be amortized:



		October 27, 2019							January 27, 2019
(in thousands)	Estimated Useful Life	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Core technologies	5-8 years	$	83,088	$	(62,674	)	$	20,414	$	167,930	$	(136,544	)	$	31,386
Customer relationships	3-10 years	6,000		(4,978		)	1,022		34,031		(31,159		)	2,872
Total finite-lived intangible assets		$	89,088	$	(67,652	)	$	21,436	$	201,961	$	(167,703	)	$	34,258

Amortization expense of finite-lived intangible assets recorded in the Statements of Income for each period was as follows:



	Three Months Ended				Nine Months Ended
(in thousands)	October 27, 2019		October 28, 2018		October 27, 2019		October 28, 2018
Core technologies	$	3,337	$	5,047	$	10,971	$	15,622
Customer relationships	433		1,433		1,850		4,299
Total amortization expense	$	3,770	$	6,480	$	12,821	$	19,921



(in thousands)
Fiscal Year Ending:	Core Technologies		Customer Relationships		Total
2020 (remaining three months)	$	3,267	$	433	$	3,700
2021	7,389		589		7,978
2022	4,655		—		4,655
2023	3,714		—		3,714
2024	1,389		—		1,389
Thereafter	—		—		—
Total expected amortization expense	$	20,414	$	1,022	$	21,436

The following table sets forth the Company’s indefinite-lived intangible assets resulting from additions to in-process research and development:



(in thousands)	Net Carrying Value
Value at January 27, 2019	$	2,300
In-process research and development through acquisitions	—
Value at October 27, 2019	$	2,300

Indefinite-lived intangible assets are tested for impairment annually on the first day of the fourth quarter or more frequently if events or changes in circumstances (each, a “triggering event”) would more likely than not reduce the carrying value of the asset below its fair value, calculated as the future discounted cash flows that asset is expected to generate. Management did not identify any triggering events during the nine months ended October 27, 2019, that would require an interim impairment analysis.