One of the original and most successful investments of Amadeus, CSR (formerly Cambridge Silicon Radio) was a leading developer and provider of single chip wireless solutions designed to support data and voice communications over short range radio links. Its use of the 2.4GHz Bluetooth personal area networking standard allowed CSR’s solutions to be implemented through a range of ICs incorporating differentiated on-chip software. These were the first Wi-Fi solutions specifically targeted at mass-market mobile phones and other pocket-sized consumer products such as digital cameras and MP3 players.

The company completed an IPO in February 2004. At the end of 2005, Amadeus exited CSR, selling its final stock holding in the open market. CSR was acquired by Qualcomm in August 2015.