Intangible Assets and Goodwill (Tables)

6 Months Ended

Sep. 30, 2015

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible assets consist of the following (amounts in thousands):



	September 30, 2015
	Gross Amount		Accumulated Amortization			Net Amount
Core and developed technology	$	778,835	$	(258,503	)	$	520,332
Customer-related	334,369		(222,817		)	111,552
Trademarks and trade names	15,730		(10,569		)	5,161
Backlog	31,804		(27,679		)	4,125
In-process technology	60,914		—			60,914
Distribution rights	5,579		(5,280		)	299
Covenants not to compete	400		(400		)	—
	$	1,227,631	$	(525,248	)	$	702,383



	March 31, 2015
	Gross Amount		Accumulated Amortization			Net Amount
Core and developed technology	$	569,942	$	(209,676	)	$	360,266
Customer-related	263,969		(193,483		)	70,486
Trademarks and trade names	15,730		(9,529		)	6,201
Backlog	26,304		(26,304		)	—
In-process technology	67,142		—			67,142
Distribution rights	5,580		(5,258		)	322
Covenants not to compete	400		(400		)	—
	$	949,067	$	(444,650	)	$	504,417

Projected Amortization Expense

The following is an expected amortization schedule for the intangible assets for the remainder of fiscal 2016 through fiscal 2020, absent any future acquisitions or impairment charges (amounts in thousands):



Year ending March 31,	Projected Amortization Expense
2016	$98,775
2017	137,051
2018	110,462
2019	93,561
2020	75,320

Goodwill Activity

Goodwill activity for the six months ended September 30, 2015 was as follows (amounts in thousands):



	Semiconductor Products Reporting Unit		Technology Licensing Reporting Unit
Balance at March 31, 2015	$	552,071	$	19,200
Additions due to the acquisition of Micrel	437,060		—
Adjustments due to acquisition of ISSC	389		—
Balance at September 30, 2015	$	989,520	$	19,200