RN41 datasheet(10/28 Pages) MICROCHIP

10 / 28 page

RN41/RN41N

DS50002280A-page 10

 2014 Microchip Technology Inc.

FIGURE 2-5:

RN41 HOST PCB EXAMPLE LAYOUT

2.5

External Antenna Types (RN41N)

The RN41N module’s antenna pin (pin 25) provides a

50-ohm impedance to external antennas. Pin 25 can

connect directly to a coaxial cable or to an antenna

connector such as a U.FL or reverse polarity SMA.

The PCB trace from pin 25 to the coaxial cable or con-

nector should be less than 0.2 inches (5 mm) for mini-

mum loss and the best impedance match. If the PCB

trace is longer, it should be a 50-ohm impedance

microstrip trace. Connect adjacent ground pins 24 and

26 to a low-impedance ground on the host PCB and the

antenna connection. Figure 2-4 gives example host

PCB layout to a U.FL connector.

Modular certification of the RN41N module was per-

formed with the external antenna types listed in

Table 2-3.

Refer to Section 3.0 “Regulatory

Approval” for specific regulatory requirements by

country.

2.6

HCI Mode

Microchip offers the Host Controller Interface (HCI)

mode in addition to the standard operational mode of its

Bluetooth modules (standard mode refers to the on-

board stack running on the module).

In HCI mode, the on-board stack is bypassed and the

module is put in a state that runs the Bluetooth base-

band. The HCI provides a command reference inter-

face to the baseband controller and the link manager,

and provides access to the hardware status and control

registers. This interface provides a uniform method for

accessing the Bluetooth baseband capabilities.

In this mode, the Bluetooth stack is no longer on-board

the module. It is offloaded to the interfacing host pro-

cessor. The Bluetooth module is used as a radio, per-

forming the lower level MAC functionalities, while the

application stack runs on the host processor.

Using the module in HCI mode enables designers to

implement profiles that are not natively supported on

the Bluetooth module.

No Copper

In these Areas

RN-41

Okay

RN-41

Best

RN-41

Okay

RN-41

Okay

TABLE 2-3:

TESTED EXTERNAL

ANTENNA TYPES

Type

Gain (dBi)

Monopole

0.56

Whip

Yagi

Note:

HCI mode is only available by ordering

part RN41HCI for UART interface; or

RN41U for USB interface.

RN41 Datasheet(PDF) 10 Page - Microchip Technology

RN41 Datasheet(HTML) 10 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Datasheet Download

Link URL