Debt (Tables)

9 Months Ended

Sep. 29, 2013

Components of Convertible Senior Notes

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

	September 29, 2013		December 31, 2012
	(in thousands)
Debt principal	$	189,998	$	190,000
Unamortized debt discount		8,448		20,104
Net carrying amount of the convertible debt	$	181,550	$	169,896

Interest Expense on Convertible Senior Notes

The interest expense on Teradyne’s convertible senior notes for the three and nine months ended September 29, 2013 and September 30, 2012 was as follows:

	For the Three Months Ended				For the Nine Months Ended
	September 29,  2013		September 30,  2012		September 29,  2013		September 30,  2012
	(in thousands)
Contractual interest expense	$	2,114	$	2,114	$	6,388	$	6,413
Amortization of the discount component and debt issue fees		4,221		3,710		12,266		10,781
Total interest expense on the convertible debt	$	6,335	$	5,824	$	18,654	$	17,194