Bluetooth® chips are board level components which broadcast in the 2.4 GHz industrial, scientific, and medical (ISM) radio band. Bluetooth is a registered trademark of the Bluetooth Special Interest Group (SIG), a trade association of electronics manufacturers that promotes Bluetooth technology and ensures compliance. Bluetooth was designed to replace short-range cable protocols, but has expanded into short-range networking. Devices that contain Bluetooth chips communicate via a standard radio frequency instead of through wires, cables, or direct user action.&nbsp; Newly manufactured devices are Bluetooth SIG 1.2 compliant and are compatible with products that use Bluetooth versions 1.0, 1.0b, and 1.1. <BR> <BR> There are several types of Bluetooth chips. Bluetooth baseband controllers combine the&nbsp;protocol stack, link controller, link manager, and host controller interface firmware of the Bluetooth specification in a single integrated circuit (IC). Bluetooth RF transceivers or radio modems are transmitters / receivers that operate in the 2.4 GHz range and comply with Bluetooth SIG requirements. Single chip solutions are Bluetooth-compliant ICs that incorporate both baseband controllers and RF transceivers. Bluetooth modules are self-contained components and Bluetooth cores are IP cores that can be loaded into field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs). Bluetooth development kits are also available for both hardware and software applications.&nbsp;<BR> <BR> Bluetooth chips belong to several power classes. Class I Bluetooth chips are used in the most powerful devices. These chips operate at 100mW (+20bB/m) and can, with a clear line of sight (LOS), receive signals from a maximum distance of 100 meters. Class II Bluetooth chips are designed for midrange applications and operate at 2.5mW(+4bB/m). With a clear LOS, devices with Class II chips can receive signals from a maximum distance of 10 meters. Class III Bluetooth chips belong to the least powerful broadcast class. They operate at 1mW(+0bB/m) and can, with a clear LOS, receive signals from up to a meter away.<BR> <BR> There are several bus interfaces for Bluetooth chips. Peripheral component interconnect (PCI) is a local bus system designed for high-end computer systems. PCI buses transfer 32 or 64 bits of data at a clock speed of 33 MHz and support three to five critical peripherals. Universal serial bus (USB) is a 12-megabit bus designed to replace connections to low-to-medium speed peripheral devices for personal computers such as keyboards, modems, and mice. IEEE 1394, a companion to the USB, is a high-performance serial bus (HPSB) that features speeds in the 400 MB to 1 GB range. IEEE 1394 is also referred to as Firewire®, a registered trademark of Apple Computer, Inc. <BR> <BR> Bluetooth chips are used in electronic equipment such as computers, cell phones, keyboards, and headphones. Bluetooth chips are also used in the devices that comprise a personal area network (PAN). Generally, a PAN is limited to a single user; however, some PANs include multiple users.