Last revised: October 23, 2024
Reviewed by: Scott Orlosky, consulting engineer

Bluetooth chips are board level components that 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.

Features

Devices that contain Bluetooth chips communicate via a standard radio frequency instead of through wires, cables, or direct user action. Newly manufactured devices are Bluetooth SIG 6.0 (Special Interest Group) compliant as of September 2024 and are compatible with products that use any earlier Bluetooth versions.

Types

There are several types of Bluetooth chips.

• Bluetooth baseband controllers combine the 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.
• 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.

Applications

Bluetooth chips belong to several power classes. Class I Bluetooth chips are used in the most powerful devices. These chips operate at 100 mW(+20 dB/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 mid-range applications and operate at 2.5 mW(+4 dB/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 1 mW(+0 dB/m) and can, with a clear LOS, receive signals from up to a meter away.

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. 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.

Bluetooth Chips FAQs

How do Bluetooth chips handle interference?

Bluetooth chips employ several techniques to handle interference, ensuring reliable communication even in environments with multiple wireless devices. Here are the key methods:

Spread Spectrum Frequency Hopping (SSFH)

Frequency hopping: Bluetooth uses a fast frequency hopping radio technique, changing its operating frequency 1,600 times per second. This enables Bluetooth devices to carry on working even in areas of high interference, as they frequently switch frequencies to avoid congested channels.

Randomized channel selection: The system generates a pair of separate channels across the 80 channels every microsecond, based on a pre-shared secret key. This quick and random channel selection prevents hackers from pinpointing the carrier frequency and reduces the likelihood of interference.

Channel Classification Management

Preferred channels: The peripheral devices can provide the centralized control point with information about their preferred channels based on their electromagnetic interference (EMI) environment. This allows the centralized control point to optimize the pairing of peripherals on the available channels, reducing the impact of EMI.

Coexistence with Other Wireless Technologies

Coexistence mechanisms: Specialty chipsets and highly integrated processors are available that implement required coexistence in multiple bands, supporting standard Wi-Fi/Bluetooth coexistence and ISM band communication. These systems can handle the bulk of the communication on one board, reducing interference from other wireless technologies.

Low Power Duty Cycle

Reduced power consumption: Bluetooth devices operate at only 2% power duty-cycle, which reduces power consumption while remaining available for device discovery and connection setup. This low power consumption helps minimize interference by reducing the overall radio frequency (RF) activity.

Bluetooth chips handle interference through techniques such as spread spectrum frequency hopping, channel classification management, coexistence mechanisms with other wireless technologies, and low power duty-cycle operation. These methods ensure reliable communication even in environments with multiple sources of interference.

How does Bluetooth 6.0 compare to previous versions in terms of performance?

With the introduction of Bluetooth 6.0, Bluetooth's focus has shifted from audio, text, and video transmission to low-power data transfer optimized for IoT applications. Here are the upgrades that come with Bluetooth 6.0.

Location services

• Bluetooth Channel Sounding, allows two devices to determine their distance from each other with centimeter-level accuracy. 

Efficiency

• Decision-Based Advertising, Filtering and Monitoring helps devices reduce power consumption by only scanning for data packets when necessary. 

Latency

• An Isochronous Adaptation Layer (ISOAL) Enhancement is included, which reduces latency by breaking large data frames into smaller chunks. 

Security

• Bluetooth 6.0 includes enhanced security.
• Extended LL (Link-layer) features: This allows devices to exchange a larger number of layer features.
• Frame Space: This no longer uses the fixed value of 150 µs and can now be shorter or longer, which makes communication more efficient.

During the transition to Bluetooth 6.0, there are still plenty of Bluetooth 5.4 devices in the market and still being produced. Version 5.4 devices carry improvements from their prior 5.3 version, most notably

• Longer battery life 
• Wider range 
• Stronger connections 
• Enhanced smart home and IoT capabilities 
• Improved audio quality 
• Encrypted Advertising Data (EAD), which allows for the encryption of data shared over periodic advertisement with responses 

What is the impact of Bluetooth 6.0 power efficiency on IoT devices?

Bluetooth 6.0 has advanced filtering capabilities that enable devices to only listen for specific data packets relevant to their application, minimizing unnecessary power expenditure on irrelevant signals. 

With features like "Monitoring Advertisers," devices can better manage when and how often they scan for nearby Bluetooth signals, leading to reduced power consumption. 

Bluetooth 6.0 is specifically designed with IoT use cases in mind, prioritizing power efficiency and optimized data transmission for low-power devices. 

It's important to note that Bluetooth 6.0 is still relatively new, so widespread device compatibility might not be as readily available as with Bluetooth 5.4. 

Also, the actual power efficiency gain will depend on the specific IoT application and how effectively the new features are implemented in device hardware. 

Bluetooth Chips Media Gallery

References

Electronics360—Chip Firms Battle Over Bluetooth for IoT

Electronics360—IoT Ubiquity Depends on Two Wireless Technologies: Wi-Fi and Bluetooth

Electronics360—Fundamentals of Bluetooth 5.3

Electronics360—New Frequency Hopping Method Stops Hackers in Their Tracks

Electronics360—Broadcom Adds Wireless Charging to Bluetooth/IoT Chip

GlobalSpec—Mobile and Wireless Communications: Key Technologies and Future Applications

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Digi-Keys Electronics