RF2115L
Pin
10
Function Description
Interface Schematic
Amplifier RF output. This is an unmatched collector output of the final
amplifier transistor. It is internally connected to pins 10, 11, 13, and 14
to provide low series inductance and flexibility in output matching. Bias
for the final power amplifier output transistor must also be provided
through two of these four pins. Typically, pins 10 and 11 are connected
to a network that creates a second harmonic trap. For 830MHz opera-
tion, this network is simply a single 2.4pF capacitor from both pins to
ground. This capacitor series resonates with internal bond wires at two
times the operating frequency, effectively shorting out the second har-
monic. Shorting out this harmonic serves to increase the amplifier’s
maximum output power and efficiency, as well as to lower the level of
the second harmonic output. Typically, pins 13 and 14 are externally
connected very close to the package and used as the RF output with a
matching network that presents the optimum load impedance to the PA
for maximum power and efficiency, as well as providing DC blocking at
the output. An additional network of a bias inductor and parallel resistor
provides DC bias and helps to protect the output from high voltage
swings due to severe load mismatches. Shunt protection diodes are
included to clip peak voltage excursions above approximately 15V to
prevent voltage breakdown in worst case conditions.
RF OUT
2
Same as pin 10.
11
12
RF OUT
GND
Same as pin 4.
Same as pin 10.
13
14
15
16
RF OUT
RF OUT
NC
Same as pin 10.
Not internally connected.
Not internally connected.
NC
This contact is the main ground contact for the entire device. Care
should be taken to ensure that this contact is well soldered in order to
prevent performance from being degraded from that indicated in the
specifications.
Pkg
Base
GND
2-42
Rev B1 010329
RFMD [ RF MICRO DEVICES ]
