Debt (Tables)

9 Months Ended

Sep. 30, 2012

Components Of Convertible Senior Notes

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

	September 30, 2012		December 31, 2011
	(in thousands)
Debt principal	$	190,000	$	190,000
Unamortized debt discount		23,732		33,902
Net carrying amount of the convertible debt	$	166,268	$	156,098

	For the Three Months Ended				For the Nine Months Ended
	September 30,           2012		October 2,  2011		September 30,           2012		October 2,  2011
	(in thousands)
Contractual interest expense	$	2,114	$	2,114	$	6,413	$	6,460
Amortization of the discount component and debt issue fees		3,710		3,263		10,781		9,484
Total interest expense on the convertible debt	$	5,824	$	5,377	$	17,194	$	15,944