User`s manual

A2541R24x – User’s Manual Page 5 of 36
Release Date 11/22/13
1. Overview
The A2541R24A and A2541R24C are surface mount 2.4GHz RF transceivers incorporating
Bluetooth
®
SMART technology per the Bluetooth v4.0 core specification. The A2541R24A has
an integral antenna, whereas the A2541R24C utilizes an external antenna through a U.FL
connector (see Table 1). These modules incorporate crystals, a step down converter, the
required RF matching and filtering for regulatory compliance as well as filtering for noise
reduction and sensitivity. They operate in the global unlicensed 2.4GHz ISM/SRD frequency
band. The modules are ideal for achieving low power, long range wireless connectivity without
having to deal with extensive protocol, RF, antenna design and regulatory compliance, and
provide quick time to market. They are 100% tested to provide consistent performance.
The A2541R24A and A2541R24C modules have received regulatory approvals for modular
devices in the United States (FCC), Canada (IC) and Europe (ETSI). The modular approval
allows the end user to place either an A2541R24A or an A2541R24C with an approved antenna
inside a finished product without having to perform costly regulatory testing for an intentional RF
radiator. Section 2.3 has information on the requirements for the end user/integrator to fulfill in
order to use the modules without intentional radiator regulatory testing.
The A2541R24A and A2541R24C are based on the CC2541 SoC transceiver from Texas
Instruments (TI). The CC2541 combines the excellent performance of a leading RF transceiver
with an industry-standard enhanced 8051 microcontroller unit (MCU), 256-KB in-system
programmable flash memory, 8-KB RAM with retention in all power modes, and many other
powerful features. The CC2541 has various operating modes, making it highly suited for
systems where ultralow power consumption is required. Short transition times between
operating modes further ensure low energy consumption. All control lines are provided at
module level for full control of the operation. Please see the user’s guide for CC2541
(www.ti.com) for how to operate, program and control these modules.
The A2541R24A and A2541R24C modules are available loaded with either “BLE Stack”
firmware from Texas Instruments (part number suffix “10”) or “EM-Ware based on BLE Stack”
firmware (part number suffix “20”) from Emmoco, a leader in embedded mobile
connectivity. More information is available for the TI BLE Stack at http://www.ti.com/tool/ble-
stack, and for Emmoco EM-Ware at http://www.emmoco.com.
The A2541R24A and A2541R24C modules measure 11 mm x 19 mm x 2.5 mm. The modules
are footprint compatible with each other.
1.1. A2541R24A
The A2541R24A has an integral antenna, providing high efficiency and near omni-directional
radiation pattern. This approach offers the lowest system cost when the application allows
collocation of radio and antenna. See Figure 9 - Figure 10 for more information on antenna
location and enclosure considerations.