ADRF5019

Data Sheet

Rev. 0 | Page 10 of 12

THEORY OF OPERATION

The ADRF5019 integrates a driver to perform logic functions

internally and to provide the user with the advantage of a

simplified positive voltage control interface. The driver features

state of the RF paths, determining which RF port is in the

insertion loss state and which path is in the isolation state (see

Table 5).

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. Therefore,

external matching networks are not required.

The ADRF5019 is bidirectional with equal power handling

RFC port or to the RF1 port or the RF2 port.

The insertion loss path conducts the RF signal between the

selected RF throw port and the RF common port. The isolation

path provides high loss between the insertion loss path and the

unselected RF throw port, which is nonreflective, by using an

internal 50 Ω termination resistor.

POWER SUPPLY

The ADRF5019 requires a positive supply voltage applied to the

Bypassing capacitors are recommended on the supply lines to

filter high frequency noise.

The ideal power-up sequence is as follows:

1. Connect to GND.

3. Power up the digital control inputs. The order of the digital

control inputs is not important. However, powering the

inadvertantly forward bias and damage 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

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

logic state.

4. Apply an RF input signal to RFC, RF1, or RF2.

The ideal power-down sequence is the reverse order of the

power-up sequence.

Single-Supply Operation

The ADRF5019 can operate with a single positive supply voltage

However, some performance degradations can occur in the

input compression and input third-order intercept.

Table 5. Control Voltage Truth Table

Digital Control Inputs

RF Paths

LS

RF1 to RFC

RF2 to RFC

High

Low

Insertion loss (on)

Isolation (off)

High

High

Isolation (off)

Insertion loss (on)

Low

Low

Isolation (off)

Insertion loss (on)

Low

High

Insertion loss (on)

Isolation (off)