NBB-302_06 Datasheet, PDF (3/8 Pages) RF Micro Devices – CASCADABLE BROADBAND GaAs MMIC AMPLIFIER DC TO 12GHz

NBB-302
Pin Function Description
Interface Schematic
1
GND
Ground connection. For best performance, keep traces physically short
and connect immediately to ground plane.
2
GND
Same as pin 1.
3
GND
Same as pin 1.
4
RF 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.
5
GND
Same as pin 1.
6
GND
Same as pin 1.
7
GND
Same as pin 1.
8
RF OUT ^{RF output and bias pin. Biasing is accomplished with an external series}
resistor and choke inductor to V_CC. 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:
RF OUT
R = ⁽---^V----^C---^C-----–----^V----^D----^E---^V---^I--^C----^E---⁾-
I_CC
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.
9
GND
Same as pin 1.
Rev A6 060124
4-11