RF5565 Datasheet, PDF (10/14 Pages) RF Micro Devices – 2.4GHz TO 2.5GHz, 802.11b/g/n WiFi FRONT END MODULE

RF5565
Theory of Operation
The RF5565 Front End Module (FEM) is designed for WiFi applications in the 2.5GHz ISM band. It can be applied in many por-
table applications such as handsets, Personal Media Players, and portable battery power equipment. This highly integrated
module can be connected directly to the battery without additional voltage regulators.
WiFi TRANSMIT MODE
The RF5565 requires a single positive supply (V_CC), a positive supply for switch controls, and a regulated supply for the V_REG to
maintain nominal bias current. The RF5565 transmit path has a typical gain of 30dB from 2.4GHz to 2.5GHz, and delivers
20dBm typical output power under 54Mbps OFDM modulation and 22dBm under 1Mbps 11b modulation. The RF5565 con-
tains basic filter components to produce a bandpass response for the transmit path. Due to space constraints inside the mod-
ule, filtering is limited to a few resonant poles and additional filters may be required depending upon the end-user’s
application. While in transmit mode, the active components are the Power Amplifier (PA) and the TX branch of the SP3T switch.
Refer to the logic control table for proper settings.
TX Biasing Instructions
• Connect the TX input to a signal generator and a spectrum analyzer at the Antenna output.
• Set V_CC to 3.3V with V_REG set to 0V.
• Turn V_REG ON and set voltage to 3.1V. V_REG controls the current drawn by the PA and it should quickly reach a quiescent cur-
rent of approximately 90mA±20mA. Care must be exercised not to exceed 3.5V on the V_REG pin or the part may be dam-
aged.
• Next set C_TX high. This pin controls the transmit branch of the SP3T.
• The SP3T controls for the off branches (C_RX and C_BT) must be set to a logic “low” (0.2V max) or grounded. In the event
that one of these branches is left floating or in a logic “high” the performance of the PA will degrade significantly. Likewise,
unused RF Ports must be terminated in 50Ω to simulate actual system conditions and prevent RF signals from coupling
back to the PA.
• Turn RF ON.
WiFi RECEIVE MODE
Within the frequency band of operation 2.4GHz to 2.5GHz, the RF5565 WiFi receive path has a typical gain of 14dB and a NF
of 2.2dB with about 12mA of current. In RX mode, only the RX branch of the SP3T and the LNA are active. Refer to the logic
control table for proper settings.
RX Biasing Instructions
• Connect the RX input (ANT/pin-10) to a signal generator and a spectrum analyzer at the RX output. A VNA may be used as
well.
• Turn LNA voltage supply ON and set the voltage to 3.3V.
• Set C_RX and LNA_EN high. This turns the LNA and the receive branch of the SP3T ON.
• The SP3T controls for the off branches (C_TX and C_BT) must be set to a logic “low” (0.2V max) or grounded. In the event
that one of these branches is left floating or in a logic “high” the performance will degrade. It is recommended to terminate
unused RF Ports in 50Ω.
• Turn RF ON.
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