Objective: This blog provides information about Bluetooth RF power class in Cypress Bluetooth devices and related certification queries.
WICED version: WICED SDK 6.2.1 or 6.4
Supported WICED device: CYW920706WCDEVAL, CYW20706 based modules
Details: Bluetooth devices may have different RF power classes depending on the Tx power and operating range of device. Following table shows the details about the classification:
| Class | Maximum Tx power | Operating range |
|---|
| class 1 | 20 dBm | ~100 meters |
| class 2 | 4 dBm | ~10 meters |
| class 3 | 0 dBm | ~1 meter |
For CYW20706 devices, by default, firmware supports class 1 with maximum Tx power +12 dBm for BR/EDR applications and +9dBm for BLE applications. There are two ways to change the Tx power, i.e. RF power class-
1. Using API to set tx power: wiced_bt_dev_set_adv_tx_power() to set the maximum Tx power for BLE advertisement and wiced_bt_dev_set_tx_power() to set maximum Tx power for connection. Please refer Configuring Transmit (Tx) Power on CYW20706 Chip - KBA228573 for more details.
2. Modifying the default CGS file. However, this method is not recommended unless customer wants to do RF test for regulatory certification.
Q. Can the certification available here RF Regulatory Certifications for CYBT-343026-01, CYBT-343029-01, CYBT-143038-01 and CYBT-343151-02 E... be used for class 2 as well?
Ans: This certification is tested under the maximum output power for class 1. Still, it can be used for class 2 as long as the configured Tx power does not extend the maximum Tx power.
Q. Is CYBT-343026-01 module NCC certified?
Ans. Yes, the module is NCC certified with NCC ID - CCAH20LP2550T0. Please find the certificate attached.
