Single-chip Bluetooth IC with Reduced Power Consumption and Toll-quality Voice
CSR launched its sixth generation of BlueCore silicon for Bluetooth. BlueCore6 includes both full support for the latest version of the Bluetooth specification (v2.1+EDR) plus the company’s AuriStream technology, which provides toll quality voice calls and is capable of a 40 percent reduction in power consumption in BlueCore6-ROM as compared with standard Bluetooth voice transmission methods, according to the company. The IC provides BlueCore6 Class 1 Bluetooth range without the need for an external power amplifier. A total 11 dB link margin improvement over BlueCore4 (+4 dBm to Tx, -7 dBm to Rx) ensures Bluetooth radio efficiency and helps improve operation across the body, for example when a Bluetooth headset connects to a mobile phone worn on the user’s belt. With AuriStream, CSR has introduced Adaptive Differential Pulse Code Modulation (ADPCM) as an enhanced voice coding method, since ADPCM scans at 32 Kbps, CVSD 64 Kbps for Bluetooth power savings in the handset. In addition, the company has reduced the power in standby and restructured how Bluetooth devices scan for other devices. Via Conditional Scan, BlueCore will wake up the minimum sections of the radio required to perform a quick scan for any activity in the 2.4 GHz band. If the radio discovers activity, it will initiate a normal Bluetooth page scan/inquiry. If not, the radio will remain asleep. Casual Scan synchronizes the periodic wake up of Bluecore6 with that of the attached baseband device; consequently, Bluecore6 does not unnecessarily wake up the host VCTXO. The Bluetooth silicon often shares a VCTXO with a mobile phone’s host system to minimize the use of additional components and save power on the cellphone system.