FROM EDN EUROPE: Silicon for Bluetooth version 1.2

BlueCore3 is CSR's (Cambridge Silicon Radio's) third-generation series of single-chip options for Bluetooth terminals. It implements all of the features of the 1.2 version of the Bluetooth standard, including those that allow it to operate close to wireless-LAN (IEEE802.11b) systems. Changes from the previous generation include lower power—by 18% on like-for-like functions; new algorithms that match the page-scan interval of Bluetooth to synchronise with host cell-phone activity to minimise power demand; and a variety of new packaging options. These options include a very small (4×4-mm) chip-scale package and a module solution (Plug and Go) that incorporates matching circuitry to allow direct connection of the antenna. BIST has also been upgraded, and the chips implement the eSCO (extended-voice-transport-protocol) feature of v1.2 to allow high-quality cordless telephony.

In response to Bluetooth's increasing use in streaming audio and similar functions, CSR has produced variants of BlueCore3 that incorporate a custom DSP core. In line with CSR's policy of keeping down costs by not using outside IP (intellectual property) that would add a royalty payment to the device cost, the company developed this architecture, called Kalimba, entirely on its own. Kalimba is a 24-bit, 32 MIPS core optimised for digital audio; it pairs, on chip variants targeting audio applications, with an 80-dB SNR stereo analogue codec. The development kit includes a full tool chain to implement custom solutions on the Kalimba core.

As with previous generations, CSR will offer a range of series-3 chips targeting specific application and price points; for example, it builds the complete module solution that includes the antenna balun with conventional pc-board technology rather than integrating passive substrate technology. This practice, CSR says, yields a module that is slightly larger than would otherwise be possible but at a lower price. Pricing is volume-dependent, but CSR says that the much-discussed target price of $5 for a single-chip solution has now been "broken by a significant margin."

CSR, +44 1223 692000, www.csr.com.