NBB-402
Pin
1
Function Description
Interface Schematic
Ground connection. For best performance, keep traces physically short
GND
and connect immediately to ground plane.
Same as pin 1.
2
3
4
GND
GND
RF IN
Same as pin 1.
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.
Same as pin 1.
5
6
7
8
GND
GND
GND
Same as pin 1.
Same as pin 1.
RF output and bias pin. Biasing is accomplished with an external series
resistor and choke inductor to V . The resistor is selected to set the
RF OUT
CC
RF OUT
DC current into this pin to a desired level. The resistor value is deter-
mined by the following equation:
(VCC – VDEVICE
)
-------------------------------------------
R =
ICC
RF IN
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. Alternatively, a constant current supply circuit may be imple-
mented. Because DC is present on this pin, a DC blocking capacitor,
suitable for the frequency of operation, should be used in most applica-
tions. The supply side of the bias network should also be well
bypassed.
Same as pin 1.
9
GND
Rev A4 031110
4-43
RFMD [ RF MICRO DEVICES ]
