Vishay Intertechnology today announced a complete Vishay RFWaves reference design for a USB-based wireless headset using a fully digital 2.4-GHz wireless link. Target applications include VoIP, PC-based cordless telephony, and PC-based "intelligent" toys.
The new design uses the Vishay RFWaves RFW322M 3-Mbps direct sequence spread spectrum (DSSS) half duplex transceiver as its core component, and includes specifications for both the wireless headset/handset and the USB dongle.
The RFW332M provides an output power of 7 dBm and receiver sensitivity of -75 dBm and delivers 16-bit PCM, 8000 samples/second voice quality. The specified operating range for the design is 6 meters and can be extended to 25 meters with the addition of an RF power amplifier. The high 2.4-GHz bandwidth of the RFW322M and the exceptional link robustness results in a very reliable and high-quality voice link. The use of printed diversity antennas for the USB further helps to overcome link losses.
The USB dongle component of the reference design specifies the use of a microcontroller to exchange voice/data packets with the PC, to execute a proprietary wireless communication protocol to transfer data over the air, and to perform an antenna diversity algorithm. The dongle uses the Vishay RFWaves RFW332M as its wireless transceiver. The dongle is powered by the USB port and typically draws 70 mA.
In the remote headset/handset unit, a microcontroller executes the proprietary communication protocol to exchange data with the USB dongle, while feeding incoming data to a high-quality mixed-signal codec. The codec provides analog signals for the speaker and microphone in the headset or handset. The remote unit draws 40 mA and is designed to run for up to four hours from a single lithium ion battery cell.
The system is designed and tested to coexist with 802.11b/g and Bluetooth and is compliant with FCC, ETSI, and Telec regulations.
Pricing for the RFW322M transceiver, which is available now, starts at $3.30 each in 10,000-piece quantities.