RF3375_06 datasheet(3/8 Pages) RFMD

3 / 8 page

4-593

RF3375

Rev A7 050524

Function

Description

Interface Schematic

1RF IN

RF input pin. This pin is NOT internally DC blocked. A DC blocking

capacitor, suitable for the frequency of operation, should be used in

most applications. DC coupling of the input is not allowed, because this

will override the internal feedback loop and cause temperature instabil-

ity.

2GND

Ground connection.

3RF OUT

RF output and bias pin. Biasing is accomplished with an external series

resistor and choke inductor to VCC. The resistor is selected to set the

DC current into this pin to a desired level. The resistor value is deter-

mined by the following equation:

Care should also be taken in the resistor selection to ensure that the

current into the part never exceeds 80mA over the planned oper-

ating temperature. This means that a resistor between the supply and

this pin is always required, even if a supply near 5.0V is available, to

provide DC feedback to prevent thermal runaway. Because DC is

present on this pin, a DC blocking capacitor, suitable for the frequency

of operation, should be used in most applications. The supply side of

the bias network should also be well bypassed.

4GND

Ground connection.

SUPPLY

DEVICE

–

()

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RF IN

RF OUT

RF3375 Datasheet(PDF) 3 Page - RF Micro Devices