Convertible Notes

The Company’s convertible notes are shown in the following table:



(In thousands)	As of September 30, 2013			As of December 31, 2012
5% Convertible Senior Notes due 2014	$	172,500		$	172,500
1.125% Convertible Senior Notes due 2018	138,000			—
Total principal amount of convertible notes	$	310,500		$	172,500

Unamortized discount - 2014 Notes	$	(12,769	)	$	(24,944	)
Unamortized discount - 2018 Notes	(29,684		)	—
Total unamortized discount	$	(42,453	)	$	(24,944	)

Total convertible notes	$	268,047		$	147,556
Less current portion	159,731			—
Total long-term convertible notes	$	108,316		$	147,556

During the second quarter of 2013, the 2014 Notes were reclassified from a long-term liability to a short-term liability as they will be due on June 15, 2014.

1.125% Convertible Senior Notes due 2018. On August 16, 2013, the Company issued $138.0 million aggregate principal amount of 1.125% convertible senior notes pursuant to an indenture (the "Indenture") by and between the Company and U.S. Bank, National Association as the trustee. The 2018 Notes will mature on August 15, 2018 (the "Maturity Date"), subject to earlier repurchase or conversion. In accounting for the 2018 Notes at issuance, the Company separated the 2018 Notes into liability and equity components pursuant to the accounting standards for convertible debt instruments that may be fully or partially settled in cash upon conversion. As of the date of issuance, the Company determined that the liability component of the 2018 Notes was $107.7 million and the equity component of the 2018 Notes was $30.3 million. The fair value of the liability component was estimated using an interest rate for a similar instrument without a conversion feature. The unamortized discount related to the 2018 Notes is being amortized to interest expense using the effective interest method over five years through August 2018.

The Company will pay cash interest at an annual rate of 1.125% of the principal amount at issuance, payable semi-annually in arrears on February 15 and August 15 of each year, commencing on February 15, 2014. The Company incurred transaction costs of approximately $3.6 million related to the issuance of 2018 Notes. In accounting for these costs, the Company allocated the costs to the liability and equity components in proportion to the allocation of proceeds from the issuance of the 2018 Notes to such components. Transaction costs allocated to the liability component of $2.8 million were recorded as deferred offering costs in other assets and are being amortized to interest expense using the effective interest method over five years (the expected term of the debt). The transaction costs allocated to the equity component of $0.8 million were recorded as additional paid-in capital. The 2018 Notes are the Company's general unsecured obligations, ranking equally in right of payment to all of Rambus’ existing and future senior unsecured indebtedness, including the 2014 Notes, and senior in right of payment to any of the Company’s future indebtedness that is expressly subordinated to the 2018 Notes.

The 2018 Notes are convertible into shares of the Company’s common stock at an initial conversion rate of 82.8329 shares of common stock per $1,000 principal amount of 2018 Notes, subject to adjustment in certain events. This is equivalent to an initial conversion price of approximately $12.07 per share of common stock. Holders may surrender their 2018 Notes for conversion prior to the close of business day immediately preceding May 15, 2018 only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on December 31, 2013 (and only during such calendar quarter), if the closing sale price of the common stock for 20 or more trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is more than 130% of the conversion price per share of common stock on the last trading day of the preceding calendar quarter; (2) during the five business day period after any five consecutive trading day period (the ‘‘measurement period’’) in which the trading price (as defined below) per $1,000 principal amount of notes for each trading day of the measurement period was less than 98% of the product of the closing sale price of the Company's common stock and the conversion rate on each such trading day; (3) upon the occurrence of specified distributions to holders of the Company's common stock; or (4) upon the occurrence of specified corporate events. On or after May 15, 2018 until the close of business on the second scheduled trading day immediately preceding the Maturity Date, holders may convert their notes at any time, regardless of the foregoing circumstances. If a holder elects to convert its 2018 Notes in connection with certain fundamental changes, as that term is defined in the Indenture, that occur prior to the Maturity Date, the Company will, in certain circumstances, increase the conversion rate for 2018 Notes converted in connection with such fundamental changes by a specified number of shares of common stock.

Upon conversion of the 2018 Notes, the Company will pay cash up to the aggregate principal amount of the notes to be converted and pay or deliver, as the case may be, cash, shares of the Company's common stock or a combination of cash and shares of the Company's common stock, at the Company's election, in respect of the remainder, if any, of the Company's conversion obligation in excess of the aggregate principal amount of the notes being converted, as specified in the Indenture.

The Company may not redeem the 2018 Notes at its option prior to the Maturity Date, and no sinking fund is provided for the 2018 Notes.

Upon the occurrence of a fundamental change, holders may require the Company to repurchase for cash all or any portion of their notes at a repurchase price equal to 100% of the principal amount of the notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date.

The following events are considered events of default under the Indenture which may result in the acceleration of the maturity of the 2018 Notes:

(1) default in the payment when due of any principal of any of the notes at maturity, upon redemption or upon exercise of a repurchase right or otherwise;

(2) default in the payment of any interest, including additional interest, if any, on any of the notes, when the interest becomes due and payable, and continuance of such default for a period of 30 days;

(3) the Company's failure to deliver cash or cash and shares of the Company's common stock (including any additional shares deliverable as a result of a conversion in connection with a make-whole fundamental change, as defined in the Indenture) when required by the Indenture;

(4) default in the Company's obligation to provide notice of the occurrence of a fundamental change, make-whole fundamental change or distribution to holders of the Company's common stock when required by the Indenture;

(5) the Company's failure to comply with any of the Company's other agreements in the notes or the Indenture (other than those referred to in clauses (1) through (4) above) for 60 days after the Company's receipt of written notice to the Company of such default from the trustee or to the Company and the trustee of such default from holders of not less than 25% in aggregate principal amount of the 2018 Notes then outstanding;

(6) the Company's failure to pay when due the principal of, or acceleration of, any indebtedness for money borrowed by the Company or any of the Company's material subsidiaries in excess of $40,000,000 principal amount, if such indebtedness is not discharged, or such acceleration is not annulled, for a period of 30 days after written notice thereof is delivered to the Company by the trustee or to the Company and the trustee by the holders of 25% or more in aggregate principal amount of the notes then outstanding without such failure to pay having been cured or waived, such acceleration having been rescinded or annulled (if applicable) and such indebtedness not having been paid or discharged; and

(7) certain events of bankruptcy, insolvency or reorganization relating to the Company or any of the Company's material subsidiaries (as defined in the Indenture).

If an event of default, other than an event of default described in clause (7) above with respect to the Company, occurs and is continuing, either the trustee or the holders of at least 25% in aggregate principal amount of the notes then outstanding may declare the principal amount of, and accrued and unpaid interest, including additional interest, if any, on the notes then outstanding to be immediately due and payable. If an event of default described in clause (7) above occurs with respect to the Company, the principal amount of and accrued and unpaid interest, including additional interest, if any, on the notes will automatically become immediately due and payable.

Interest expense related to the notes for the three and nine months ended September 30, 2013 and 2012 was as follows:



	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2013		2012		2013		2012
	(In thousands)
2014 Notes coupon interest at a rate of 5%	$	2,156	$	2,156	$	6,469	$	6,469
2014 Notes amortization of discount and debt issuance costs at an additional effective interest rate of 11.7%	4,416		3,789		12,650		10,856
2018 Notes coupon interest at a rate of 1.125%	$	194	$	—	$	194	$	—
2018 Notes amortization of discount and debt issuance costs at an additional effective interest rate of 5.5%	$	719	$	—	$	719	$	—
Total interest expense on convertible notes	$	7,485	$	5,945	$	20,032	$	17,325