Cambridge Silicon Radio (CSR) officially launched its fourth-generation Bluetooth silicon last month at the WiCon World in Amsterdam, The Netherlands. Designed to meet the latest specs of Enhanced Data Rate (EDR) Bluetooth standard developed by the Bluetooth Special Interest Group (SIG), CSR's single radio and baseband IC BlueCore4 delivers data rates that are threetimes faster than current v1.2 Bluetooth devices, as well as lower power consumption for Bluetooth mobile phones or headsets.

As per the data sheet, Bluetooth EDR offers maximum data transfer rates of 2.1 Megabits per second (Mbps) compared to the current 721 kilobits per second (kbps) for v1.2 standard rate. Fully backward-compatible with existing Bluetooth v1.1 and v1.2 devices, the Bluecore4 uses a phase-shift keying (PSK) modulation scheme in place of the Gaussian frequency shift keying (GFSK) to achieve a faster data rate. As a result, it can transmit more bits in each symbol of the packet-payload when it is sent over the radio link.

According to CSR, the fourth-generation Bluetooth device is being offered in two versions. While one it architected to work with external Flash memory, the other uses mask-ROM. BlueCore4-External comes in an 8 mm × 8 mm BGA package and is a flexible solution for applications that demand the ability to upgrade quickly. And BlueCore4-ROM offers lower costs and a much smaller footprint (3.8 mm × 4 mm) in a chip-scale package, or 6 mm × 6 mm in a BGA, which is pin-compatible with BlueCore2-ROM and BlueCore3-ROM.

BlueCore4 offers increased on-board RAM of 48 Kbytes compared to 32 Kbytes on previous BlueCore silicon. Some of this extra memory is required for additional buffer space to handle the Enhanced Data Rate, while the rest ensures that future specifications such as Scattermode will be fully supported.

BlueCore4-External and BlueCore4-ROM will initially bring the benefits of Bluetooth EDR's faster data rates to some of these existing key Bluetooth markets, speeding file transfers, reducing power consumption and enabling the operation of multiple, simultaneous links. It will also open up some potential new application areas for the technology. As mobile phones integrate higher resolution digital cameras, transfering the image files becomes time consuming — EDR Bluetooth means that a 1 Mbyte image download, which currently takes about 12 seconds, will now only take four seconds.

As ‘One Phone’ converged cordless phone (using Bluetooth) and cellular phones (using 2.5 or 3G) with a single telephone number become popular, the higher speed Bluetooth radio connection from the cordless home or business access point will allow for the simultaneous transfer of more data while the telephone call is being placed over the fixed-line infrastructure.

The Bluetooth SIG is incorporating Bluetooth EDR as an addendum to the current v1.2 specification. CSR is sampling BlueCore4-External now, with full production in September. BlueCore4-ROM will sample in Q3 2004 with mass production planned to start in Q4 2004. BlueCore4 is sampling now with major OEM customers.

For more information, visit www.CSR.com