RB540 Class I, Bluetooth Audio Module

Featured Product from Radicom Research, Inc.

The RB540 series features a Class 1 Bluetooth data with simultaneous audio module for system integrators. The RB540 comes complete with DSP, stereo CODEC, flash memory and on board antenna. The module offers superior audio quality, power consumption and radio performance making it ideal for high quality Bluetooth headset designs and most stereo and mono audio applications.

The embedded DSP core is an open platform digital signal coprocessor allowing product-enhancing features such as advance audio decoding (MP3, AAC, AAC+), speech recognition, text-to-speech, echo cancellation and noise reduction.

With Class 1 radio, transmission power up to 20dBm, the RB540 series can connect to other Bluetooth devices such as MP3/MD/CD players, mobile phones, and desktop or notebook computers, PDA etc., in range up to 650 ft. (200 meters).

The RB540 series combines Bluetooth Basic Rate (BT 3.0) technology to provide increased throughput, reduced battery consumption and improved security. It also provides faster pairing and allows superior performance in the presence of interference from 802.11 Wi-Fi wireless devices and other 2.4GHz radios.

The RB540 series has on board flash memory available to upgrade the module’s firmware, modify parameters, or implement custom features. Radicom is capable to modify the firmware to meet ODM / OEM requirements and create custom Bluetooth functionality to meet OEM’s specific needs.

TrueWirelss (TWS) technology allows for streaming A2DP music on the master device which then relays the audio stream to a slave device. It also supports sending data or command to control master and slave through a smart phone or tablet.

With Radicom Research’s proprietary True Audio Data (TAD) protocol, the RB540 allows smart phones to transmit data to control devices during music streaming without affecting the audio signal. It supports audio A2DP, handset, hands-free wireless profiles.

There are two platforms available: The RB540 is a surface mount PCB module with on-board antenna. The RB540HM is a DIP, through-hole module continuing the popular Radicom “HM” footprint of 1” x 1”. The RB540HM also has an U.FL connector built in for attaching an antenna cable allowing flexibility to place antenna at a desired location.


  • Class 1 radio, transmission power up to 20dBm
  • Bluetooth V3.0, V2.1+EDR  support
  • UART / SPI interfaces (optional for special firmware)
  • Small sizes: 1.55” x 0.70” x 0.10” (RB540-a), 1.00" x 1.33" x 0.25" (RB540HM-c)
  • Serial Port Profile (SPP) support
  • A2DP, AVRCP, HFP / HSP support
  • 64MIPS Kalimba DSP co-processor
  • Up to 16Mbits flash memory on board (firmware dependent – 8Mbits typical)
  • Secure communications with 128-bit encryption (optional)
  • On-board antenna (RB540-a, RB540HM-a)
  • On-board U.FL connector for external antenna (RB540HM-c)
  • Support 802.11 wireless coexistence
  • -40°C to +85°C extended temperature operating
  • RoHS compliant
  • FCC, IC and CE (pending)


  • High Quality Stereo & Mono Headsets

  • Bluetooth Speakers

  • AV Transmitters

  • Hand-free Car Kits

  • MP3 Players

  • VoIP Headsets

  • Audio Dongles

  • Automotive Wireless Gateway

  • Cordless Phone (TX/RX)

  • Intercom

  • Long Range Locators



1.55” x 0.70”x 0.10” (RB540-a), 1.00” x 1.33” x 0.25”(RB540HM-c)

Device Type

Embedded Bluetooth OEM modules



Data Link Protocol

Bluetooth V3.0, V2.1+EDR


2.402 – 2.480 GHz

Transmit Power

20dBm max.

Nominal Sensitivity


Bluetooth Class

Class 1


Up to 200 meters

On Board Flash

8Mbits, 32Mbits (optional)


128-bit encryption (optional)

Power Consumption

Standby: <4mA, SCO Link: <43mA (under calling), A2DP Streaming: <45mA (music playing)

Supply Voltage: VDD

3.0V - 3.6V


Optional Chip On-board or U.FL connector for external antenna (HM)

Baseband Crystal OSC


RF Input Impedance

50 ohms

Receiver IF Frequency


Receiving Signal Range

-90 to –20dBm typical


1600hops/sec, 1MHz channel space

Operating Temperature

-40ºC to +85ºC

Storage Temperature

-40ºC to +125ºC


RoHS compliant