DAN-191 Datasheet, PDF (1/3 Pages) Exar Corporation – EXAR UARTS IN BLUETOOTH APPLICATIONS

DAN191
EXAR UARTS IN BLUETOOTH APPLICATIONS
April 2008
EXAR UARTS IN BLUETOOTH APPLICATIONS
1.0 INTRODUCTION
This application note describes why Exar's XR20M1170 is ideal for adding Bluetooth® capability to any
application. Some example applications where Bluetooth can be used are SmartPhones, PDA and GPS
applications.
2.0 BLUETOOTH ENHANCED DATA RATE
The Bluetooth Core Specification Version 2.1 + EDR was published in July 2007. In this version, the Enhanced
Data Rate (EDR) modulation mode supports data rates up to 3 Mbps.
3.0 UART HOST CONTROLLER INTERFACE
There are usually a few host controller interfaces (HCI) available on Bluetooth modules/chipsets to
communicate with a host controller or system. However, one of the simplest ways is for the host controller/
system to communicate via a UART interface. As a result of the Enhanced Data Rate, newer Bluetooth
modules/chipsets have UARTs on their HCI that support data rates of 3Mbps.
However, the maximum data rate of the built-in UART on the host controller/system can only typically support
data rates up to 115200 bps. Hence, there is a need for high performance Exar UARTs.
FIGURE 1. BLUETOOTH APPLICATION PROBLEM
?
UART
MCU
115.2 Kbps
3 Mbps
UART
Bluetooth
Module/
Chipset
1