How to Make Extended Range BLE Modules to Work as a Normal Module - KBA219463

Version: **

 

Question:

How to Use XT/XR Modules without making use of the Power Amplifier (Normal BLE Module)?

 

Answer:

In existing BLE XT/XR Modules, if the PA/LNA is not enabled, ideally, there would be no radiations, but practically, there would be some leakage radiations. In this case, the range would be somewhere around a few centimeters. Sometimes, it might be necessary to use these modules for shorter range and/or might require them to operate at lower power.

 

The steps to enable the extended range functionality is available in the datasheets of these modules and also in the AN96841 - Getting Started With EZ-BLE™ Module application note. An important step in this procedure is including the lines given below under CYBLE_EVT_STACK_ON. By writing '1' to both CSD and CPS pins, the PA is enabled and the increased gain can be obtained.

 

CSD_Write(1);
CPS_Write(1);

 

/* Configure the Link Layer to automatically switch PA control pin P3[2] and LNA control pin P3[3] */
CY_SET_XTND_REG32 ((void CYFAR *)(CYREG_BLE_BLESS_RF_CONFIG), 0x0331);
CY_SET_XTND_REG32 ((void CYFAR *)(0x40030008), 0x80000302);

 

If these modules must be used as a non-XT module, it can be done by putting the PA/LNA in bypass mode. To do so, just write a '1' to the CSD pin and a '0' to the CPS pin; i.e.,

 

CSD_Write(1);
CPS_Write(0);

 

This puts the PA/LNA in bypass mode and the output Tx power will be as set by you either in the BLE Component configuration or in the firmware (+3 dBm to -18 dBm). In the bypass mode, the PA/LNA module will not add any gain. This information about the bypass mode can be obtained from the datasheet of the Skyworks SE2438T module.

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