Data Sheet

ADRF5032

THEORY OF OPERATION

analog.com

Rev. 0 | 9 of 11

The ADRF5032 can connect to CMOS/LVTTL-compatible control

interfaces directly.

The CTRL pin determines which RF port is in the insertion loss

state and in the isolation state. See Table 6 for the control voltage

truth table.

RF INPUT AND OUTPUT

The RF ports (RFC, RF1, and RF2) are DC-coupled to 0 V, and no

DC-blocking is required at the RF ports when the RF line potential

is equal to 0 V.

The RF ports are internally matched to 50 Ω. However, impedance

matching on transmission lines can be used to improve insertion

loss and return loss performance at high frequencies.

The ADRF5032 is bidirectional with equal power-handling capabili-

ties. The RF input signal can be applied to the RFC port or the

selected RF throw port.

The insertion loss path conducts the RF signal between the select-

ed RF throw port and the RF common port. The isolation paths

provide high loss between the insertion loss path and the unselect-

ed RF throw port that is reflective.

The power handling of the ADRF5032 derates with frequencies

below 3 GHz. See Figure 2 for derating of the RF power towards

lower frequencies.

POWER SUPPLY

The ADRF5032 requires that a positive supply voltage is applied

to the VDD pin and a negative supply voltage to the VSS pin.

Bypassing capacitors are recommended on the supply lines to

minimize RF coupling.

The unselected RF port of the ADRF5032 is reflective. The isolation

path provides high isolation between the unselected port and the

insertion loss path.

The ideal power-up sequence is as follows:

1. Connect GND.

2. Power up VDD and VSS. Power up VSS after VDD to avoid

current transients on VDD during ramp up.

3. Power up the digital control inputs. The relative order of the log-

ic control inputs is not important. However, powering the digital

control inputs before the VDD supply can inadvertently forward-

bias and damage the internal ESD-protection structures.

4. Apply signals to the RF input port. The design is bidirectional—

the input signal can be applied to the RFC port while the RF

throw ports are outputs or vice versa.

The ideal power-down sequence is the reverse of the above.

Table 6. Control Voltage Truth Table

Digital Control Input

RF Path

CTRL

RF1 to RFC

RF2 to RFC

Low

Isolation (off)

Insertion loss (on)

High

Insertion loss (on)

Isolation (off)