4-43
NBB-402
Rev A6 060124
Pin
Function
Description
Interface Schematic
1GND
Ground connection. For best performance, keep traces physically short
and connect immediately to ground plane.
2GND
Same as pin 1.
3GND
Same as pin 1.
4RF 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.
5GND
Same as pin 1.
6GND
Same as pin 1.
7GND
Same as pin 1.
8RF 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. 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.
9GND
Same as pin 1.
R
V
CC
V
DEVICE
–
()
I
CC
-------------------------------------------
=
RF OUT
RF IN