NLB-310 datasheet(3/8 Pages) RFMD

3 / 8 page

4-141

NLB-310

Rev A6 040409

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. For best performance, keep traces physically short

and connect immediately to ground plane.

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 maximum datasheet operating cur-

rent over the planned operating 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 run-

away. Because DC is present on this pin, a DC blocking capacitor, suit-

able for the frequency of operation, should be used in most

applications. The supply side of the bias network should also be well

bypassed.

4GND

Same as pin 2.

VCC VDEVICE

–

()

ICC

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RF OUT

RF IN

NLB-310 데이터시트(PDF) 3 Page - RF Micro Devices