Reference Design

Tiny, advanced Bluetooth headset ref design, $5 eBOM

BlueVox2 mono headset design with an eBOM of $5, world’s lowest cost advanced Bluetooth headset; features extremely low power consumption and zero cost noise reduction, support for Bluetooth version 2.1+EDR.

Source: CSR
3/4/2008

CSR’s design includes: AuriStream™ for superior voice quality; simultaneous connection of multiple devices; and support for Bluetooth version 2.1+EDR. BlueVox2 also presents headset manufacturers with the opportunity to design the world’s smallest Bluetooth headsets through an ultra small 4.5x5.5 mm BGA package option.

The low eBOM of $5 includes the BlueVox2 QFN chip, together with all of the components necessary for a Bluetooth mono headset mounted on a four-layer printed circuit board. BlueVox2 is incredibly power efficient, permitting 15 hours talk time from a small 120 mAh battery. BlueVox2’s features include hardware-based noise reduction technology at no extra cost.

The design also raises voice quality to the standard of a landline phone by using CSR’s AuriStream CODEC. AuriStream delivers an ITU-T mean opinion score (MOS) of up to 4.2 out of 5, even without the additional benefits of noise reduction. In comparison, headsets using only the more standard CVSD CODECs achieve a MOS of around 2.46. Calls made using AuriStream are of noticeably better quality.

BlueVox2 is the first ever ROM headset design to allow two or more Bluetooth devices to be connected to the same headset. This means that with one headset it is possible to take calls from both a work and personal phone or a phone and a VoIP dongle. The feature doesn’t impact the power consumption and is designed to be easy and intuitive to use.

BlueVox2 is the world's first ROM-based design to adhere to Bluetooth v2.1+EDR, offering Secure Simple Pairing, which greatly simplifies the headset-to-phone pairing process while significantly increasing Bluetooth device security. With the enhanced inquiry scan Bluetooth v2.1 can also gather and present a greater range of information when searching for devices, including a list of services each device supports.

BlueVox2 integrates onto a single chip the world’s leading Bluetooth radio design, CODECs for the microphone and speakers, power management, a battery charger and a microprocessor to run virtual machine applications. BlueVox2’s silicon, based on CSR’s BlueCore6-Audio ROM, features a low cost 7x7 mm QFN package as well as a 4.5x5.5 mm BGA package option for the world’s smallest headset IC. The performance of BlueVox2’s radio is exemplary, with TX+8 dBm and Rx -90 dBm helping to overcome cross-body issues and increase range.