Debt (Tables)

9 Months Ended

Sep. 28, 2014

Components of Convertible Senior Notes

The tables below represent the components of Teradyne’s convertible senior notes:

	September 28, 2014		December 31, 2013
	(in thousands)
Debt principal	$	—	$	189,998
Unamortized debt discount		—		4,290
Net carrying amount of the convertible debt	$	—	$	185,708

Interest Expense on Convertible Senior Notes

The interest expense on Teradyne’s convertible senior notes for the three and nine months ended September 28, 2014 and September 29, 2013 was as follows:

	For the Three Months Ended				For the Nine Months Ended
	September 28, 2014		September 29, 2013		September 28, 2014		September 29, 2013
	(in thousands)
Contractual interest expense	$	—	$	2,114	$	1,757	$	6,388
Amortization of the discount component and debt issue fees		—		4,221		4,493		12,266
Total interest expense on the convertible debt	$	—	$	6,335	$	6,250	$	18,654