Data Sheet

ADRF5532

THEORY OF OPERATION

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Rev. A | 9 of 11

The ADRF5532 requires a positive supply voltage applied to the

VCC. Use the bypass capacitors on the supply lines to filter noise.

See the application circuit for the capacitor values and configura-

tion.

SIGNAL PATH SELECTION

The ADRF5532 supports two operational states: transmit operation

and receive operation.

The transmit operation is enabled when 0 V is applied to T/R. In

the transmit operation, the signal paths are connected from ANT to

TERM. Additionally, the ADRF5532 disables the power to the LNA,

reducing the current and thermal contributions from the LNA.

The receive operation is enabled when 5 V is applied to T/R. In

the receive operation, the signal paths are connected from ANT to

RXOUT. During the receive operation, the switch is in an isolation

state.

BIASING SEQUENCE

To bias up the ADRF5532, perform the following steps:

1. Connect any GND pin to ground.

2. Power up the supply input VCC.

3. Apply digital control input T/R. Applying the T/R control be-

fore applying the VCC supply inadvertently forward biases and

damages the internal ESD protection structures. To avoid this

damage, use a series 1 kΩ resistor to limit the current flowing

into the control pin. Use pull-up or pull-down resistors if the

controller output is in a high-impedance state after VCC is

powered up and the control pins are not driven to a valid logic

state.

4. Apply an RF input signal.

To bias down, perform these steps in the reverse order.

Table 6. Truth Table: Signal Path Selection

T/R

Signal Path Selection

Transmit Operation (ANT to TERM)

Receive Operation (ANT to RXOUT)

Low

On

Off, LNA powered down

High

Off, isolation state

On