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“Connectivity hub” chip bundles 4 wireless functions

The latest in CSR’s BlueCore series of wireless chips is BlueCore7, which the company now describes as a connectivity hub for mobile phone handsets, combines four radio technologies on to one IC. It integrates Bluetooth, Bluetooth low energy (otherwise known as Ultra Low Power Bluetooth or WiBree), FM radio – receive and transmit – and GPS.

The Bluetooth radio complies with the v2.1 + EDR standard, with +10 dBm transmit power and -91 dBm receiver sensitivity for best range and “cross-body” performance (handset to headset). The transceiver includes CSR’s AuriStream voice CODEC, which produces the quality of a fi xed line call, when using a Bluetooth connection, and is capable of a 30% reduction in power consumption. The codec activates when each end of the link is equipped to use it; otherwise, the link reverts to a CVSD codec. Inbuilt speaker drivers also allow users to connect headphones directly to the device.

On the same chip, a GPS receiver implements the RF portion of CSR’s eGPS architecture. Using the portable device’s host processor, eGPS uses a combination of GPS signals and cellular network data to provide position information in diffi cult GPS reception areas.

By integrating a transmit and receive FM radio with Bluetooth, handset designers can, CSR says, offer these features using less space, fewer components and at lower cost. BlueCore7 allows the Bluetooth and FM radios to work without interference, either independently or together, to allow users to stream FM radio from a handset to a pair of Bluetooth headphones. The FM receiver has -110dBm sensitivity. You might use the FM transmit function to play music over a car radio. With a maximum output power of +4.5 dBm, the chip can use an ineffi cient FM antenna that’s internal to the handset.

CSR says that all of the chip’s four functions can work together in any combination, without intervention from operating- system-level. You will, in other words, be able to maintain GPS tracking while using a Bluetooth, or FM, radio link. In designing the chip, the company adds, it has been able to take advantage of the fact that many subsystems are common to more than one of the radio functions. For the designer, the result is size and cost reduction, and for the handheld device market, an increased “attach rate” of GPS terminals – at an incremental cost for adding GPS of under $1.

In common with other CSR parts, the chip comes with example designs, and you can explore its features with the company’s Casira evaluation platform. The IC has a serial interface to a flash memory device, that can bypass the on-chip ROM. You can fully develop your application using external fl ash memory and only order a ROM version when code is fi nal.

CSR, www.csr.com