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RF2642
Rev A8 DS060925
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.
Pin
Function
Description
Interface Schematic
1GND
Ground connection. For best performance, keep traces physically short
and connect immediately to ground plane. This pin is internally connected
to the die flag.
2RF OUT
Output match of the second stage of the power amplifier driver. This ampli-
fier output pin is open collector. It is matched to 50
Ω externally using a
simple LC match. Refer to the application schematic.
3RF GND2
The ground connection for the second stage of the power amplifier driver.
The inductance between this pin and the ground plane determines the
gain of the second stage. Increased inductance results in reduced gain.
On the evaluation board, the emitter ground inductance is set by the length
of the PCB trace connected between this pin and the ground. By sliding a
0
Ω ground jumper along this line, the inductance, and hence the gain, may
be varied.
The evaluation board is shipped with the 0
Ω jumper very close to the part,
resulting in minimum inductance, and therefore maximum second stage
gain. This translates to higher output IP3 and maximum ACPR1. This set-
ting results in performance 6dB better than the ACPR1 minimum specifica-
tion of 50dBc in the CDMA IS-95 specification for a POUT=+5dBm.
4RF GND1
The ground connection for the first stage of the power amplifier driver. The
inductance between this pin and the ground plane determines the gain of
the first stage. Increased inductance results in reduced gain.
On the evaluation board, the emitter ground inductance is set by the length
of the PCB trace connected between this pin and the ground. By sliding a
0
Ω ground jumper along this line, the inductance, and hence the gain, may
be varied.
The evaluation board is shipped with the 0
Ω jumper far away from the
part, resulting in maximum inductance, and therefore minimum first stage
gain.
More gain may be obtained by shifting the 0
Ω jumper toward the part. A
maximum total gain of 40dB may be achieved if the first stage is set to
minimum emitter inductor trace length.
See pin 3.
5VPA1
Power supply pin for the first stage power amplifier. External components
provide tuning for the interstage match.
6RF IN
RF input to the power amplifier. This input is DC-coupled, so an external
blocking capacitor is needed if the pin is connected to a DC path.
7PD
Power Down control When this pin is low, the amplifier section of the IC is
shut off. When this pin is high, the amplifier section of the IC is turned on.
The upconverter portion of the IC remains on regardless of the state of PD.
8MIX OUT
Output for the upconverting mixer. This input is DC-coupled, so an external
blocking capacitor is needed if the pin is connected to a DC path. The out-
put impedance is 50
Ω.
9GND
Same as pin 1.
RF OUT
Gain
Select
PCB
Trace
VPA1
Bias
RF IN
MIX OUT