Datasheet RN41, RN41N (Microchip) - 10

link to page 9 link to page 10
RN41/RN41N FIGURE 2-5: RN41 HOST PCB EXAMPLE LAYOUT
RN-41 Best RN-41 RN-41 No Copper RN-41 In these Areas Okay Okay Okay
2.5 External Antenna Types (RN41N) 2.6 HCI Mode
The RN41N module’s antenna pin (pin 25) provides a Microchip offers the Host Controller Interface (HCI) 50-ohm impedance to external antennas. Pin 25 can mode in addition to the standard operational mode of its connect directly to a coaxial cable or to an antenna Bluetooth modules (standard mode refers to the on- connector such as a U.FL or reverse polarity SMA. board stack running on the module). The PCB trace from pin 25 to the coaxial cable or con- In HCI mode, the on-board stack is bypassed and the nector should be less than 0.2 inches (5 mm) for mini- module is put in a state that runs the Bluetooth base- mum loss and the best impedance match. If the PCB band. The HCI provides a command reference inter- trace is longer, it should be a 50-ohm impedance face to the baseband controller and the link manager, microstrip trace. Connect adjacent ground pins 24 and and provides access to the hardware status and control 26 to a low-impedance ground on the host PCB and the registers. This interface provides a uniform method for antenna connection. Figure 2-4 gives example host accessing the Bluetooth baseband capabilities. PCB layout to a U.FL connector. In this mode, the Bluetooth stack is no longer on-board Modular certification of the RN41N module was per- the module. It is offloaded to the interfacing host pro- formed with the external antenna types listed in cessor. The Bluetooth module is used as a radio, per- Table 2-3. Refer to
Section 3.0 “Regulatory
forming the lower level MAC functionalities, while the
Approval”
for specific regulatory requirements by application stack runs on the host processor. country. Using the module in HCI mode enables designers to
TABLE 2-3: TESTED EXTERNAL
implement profiles that are not natively supported on
ANTENNA TYPES
the Bluetooth module.
Type Gain (dBi) Note:
HCI mode is only available by ordering Monopole 0.56 part RN41HCI for UART interface; or RN41U for USB interface. Whip 8 Yagi 15 DS50002280A-page 10  2014 Microchip Technology Inc. Document Outline 1.0 Device Overview 1.1 MCU Interface 1.2 ASCII Command and Data Interface TABLE 1-1: Environmental Conditions TABLE 1-2: Electrical Characteristics TABLE 1-3: Module Dimensions TABLE 1-4: Radio Characteristics TABLE 1-5: Digital I/O Characteristics TABLE 1-6: Pin Description 2.0 Application Information 2.1 Reset Circuit 2.2 Factory Reset Using GPIO4 2.3 Connection Status TABLE 2-1: GPIO5 Status TABLE 2-2: GPIO2 Status 2.4 Module Mounting Details 2.5 External Antenna Types (RN41N) TABLE 2-3: Tested External Antenna Types 2.6 HCI Mode 2.7 Soldering Recommendations 2.8 SPI Interface 2.9 Bluetooth SIG QDID 2.10 Application Schematic 3.0 Regulatory Approval 3.1 United States 3.2 Canada 3.3 Europe TABLE 3-1: RN41 European Compliance Testing TABLE 3-2: RN41N European Compliance Testing 3.4 Australia 3.5 New Zealand 4.0 Ordering Information TABLE 4-1: Ordering Information Class 1 Bluetooth® Module with EDR Support Worldwide Sales and Service