Bluetooth IC / chipset

01

Read the radio, power and package data

As an example, Texas Instruments' data sheet for the CC2640R2F wireless MCU lists a 2.4 GHz transceiver compatible with Bluetooth Low Energy 5.1 and earlier LE specifications (with LE Coded long-range and LE 2 Mbit PHYs), receiver sensitivity of −97 dBm for BLE, programmable output power up to +5 dBm and a 102 dB link budget. It integrates an Arm Cortex-M3 at up to 48 MHz with 275 KB of non-volatile memory and up to 28 KB SRAM, a separate low-power sensor controller, a 12-bit ADC, AES-128 security and an on-chip DC/DC converter. [1]

Its supply range is 1.8–3.8 V, with active receive at 5.9 mA, transmit at 6.1 mA (0 dBm) and 9.1 mA (+5 dBm), standby of 1.1 µA with RTC and RAM retention, and shutdown of 100 nA; packages run from a 2.7 × 2.7 mm DSBGA with 14 GPIOs to a 7 × 7 mm VQFN48 with 31 GPIOs. The data sheet lists it as suitable for systems targeting ETSI EN 300 328, EN 300 440, FCC CFR 47 Part 15 and ARIB STD-T66. [1]

Editorial calculation: the 102 dB link budget is the +5 dBm output minus the −97 dBm sensitivity; any loss in the antenna, matching or enclosure comes off this figure, so compare chips on the same output power and PHY. [1]

Give the supplier the Bluetooth version and features needed (LE, Classic, long range, audio), required range and antenna design, battery type and life target, transmit and receive duty, application processor and memory needs, peripherals and GPIO count, package and assembly constraints, operating temperature, target markets and certifications, software stack and qualification support, and annual volume and supply lifetime.

02

Check the radio rules for the band

US rule 47 CFR 15.247 covers intentional radiators in 902–928, 2400–2483.5 and 5725–5850 MHz. Frequency hopping systems in 2400–2483.5 MHz must use at least 15 channels, with average occupancy on any channel no more than 0.4 s within 0.4 s times the number of channels; their peak conducted output is limited to 1 W with at least 75 non-overlapping channels and 0.125 W otherwise. Digitally modulated systems need a 6 dB bandwidth of at least 500 kHz, are limited to 1 W conducted output, and their power spectral density must not exceed 8 dBm in any 3 kHz band; the limits assume antenna gain not over 6 dBi, with output reduced by the excess above that. [2]

Editorial note: the chip's data sheet states which regulations it targets, but certification applies to the finished product; ask the supplier for reference designs and test reports that match your antenna and enclosure.

03

Compare chip sensitivity and power with the Bluetooth minimums

The Bluetooth SIG, which maintains the Bluetooth specification, states that devices must achieve a minimum receiver sensitivity of -70 dBm to -82 dBm depending on the PHY, and that "average implementations of the Bluetooth LE 125K (Coded) PHY are achieving a receiver sensitivity of -103 dBm." It gives the supported transmit power range as -20 dBm (0.01 mW) to +20 dBm (100 mW), in the 2.4 GHz band from 2400 to 2483.5 MHz. [3] Editorial calculation: the −97 dBm BLE sensitivity in TI's CC2640R2F data sheet [1] is 15 dB below the −82 dBm end of the SIG minimum range, and its +5 dBm maximum output is 15 dB under the +20 dBm top of the SIG range.

The SIG names spectrum, PHY, receiver sensitivity, transmit power, antenna gain and path loss as the factors that set range, and says Bluetooth devices "typically achieve an antenna gain in the range of –10 dBi to +10 dBi." It notes that higher transmit power extends range but increases the device's power consumption. [3] Editorial note: ask the chip supplier for sensitivity and output power on the PHY you will use, with the current drawn at that output power.

04

Decide between a Bluetooth-only chip and a Wi-Fi plus Bluetooth SoC

Some products need Wi-Fi as well as Bluetooth LE, for example to set up a device from a phone over Bluetooth and then connect it to a network. Espressif's ESP32-C3 is an example of the combined approach: a single-core Wi-Fi and Bluetooth 5 (LE) microcontroller SoC built on a 32-bit RISC-V core with a maximum clock of 160 MHz, 22 configurable GPIOs and 400 KB of internal RAM, offered in variants with integrated or external flash. Espressif states that it supports Bluetooth LE long range (LR), Bluetooth LE SIG Mesh and Espressif Wi-Fi Mesh, and that it can also run as a radio for an external host MCU through its ESP-AT and ESP-Hosted software. [4]

For security, Espressif lists RSA-3072-based secure boot, AES-128/256-XTS-based flash encryption, a digital signature peripheral and an HMAC peripheral for device identity, with hardware acceleration for cryptographic algorithms; the TI CC2640R2F above lists AES-128. [4] [1]

Editorial calculation: against the CC2640R2F's Cortex-M3 at up to 48 MHz, up to 28 KB SRAM and 31 GPIOs in the 7 × 7 mm VQFN48, the ESP32-C3's 160 MHz is about 3.3 times the clock and 400 KB about 14 times the RAM, with 9 fewer GPIOs than the largest CC2640R2F package. These are vendor headline figures; compare current draw, sensitivity and output power from each data sheet before choosing on processor size. [4] [1]

05

Trace what the chip integrates

This is a functional reference built from the sources cited; it is not one maker's design.

06

Fill the specification fields with values for your device

A Bluetooth IC selection needs values for your product. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.

07

Send the feature, power and market data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Features: [Bluetooth version; LE/Classic; long range; audio]
Range: [target; antenna]
Power: [battery; life; duty]
Processor: [memory; peripherals; GPIO]
Package: [type; size]
Temperature: [range]
Markets: [regulations; certifications]
Supply: [volume; lifetime]

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