RF2667
Pin
14
Function Description
Interface Schematic
BIAS
Selects between CDMA and FM mode. This is a digitally controlled
input. A logic “high” (≥VCC-0.7V ) selects CDMA mode. A logic “low”
IN SEL
DC
(<0.5V ) selects FM mode. The impedance on this pin is 30kΩ.
DC
60 k
Ω
60 k
Ω
IN SEL
Balanced Baseband Output of Q Mixer. This pin is internally DC biased
and should be DC blocked externally. This output is active in both
CDMA and FM modes. The output can be used in a single-ended con-
figuration by leaving one of the two pins unconnected, however half the
output voltage will be lost. Each pin should be loaded with 2.5kΩ. The
balanced load should be 5kΩ. The single-ended output impedance is
1.2kΩ, while the balanced output impedance is 2.4kΩ.
15
Q OUT-
VCC
VCC
1.2 k
Ω
1.2 kΩ
Q OUT+
Q OUT-
Same as pin 15, except complementary output.
Same as pin 6.
See pin 15.
16
17
18
Q OUT+
GND
Balanced AGC Output/Demod Input. This balanced node is pinned out
to allow shunt filtering of the AGC output signal as it enters the demod-
ulator. The basic configuration of the filter should consist of a shunt
inductor and shunt capacitor, both connected to the power supply, as
the internal circuitry requires this power supply connection through the
inductor to operate.
FL-
FL- FL+
VCC2
VCC2
VCC1
VCC1
7
1.2 k
Ω
1.2 kΩ
Same as pin 18, except complementary.
Same as pin 6.
See pin 18.
19
20
21
FL+
GND
I OUT+
Balanced Baseband Output of I Mixer. This pin is internally DC biased
and should be DC blocked externally. This output is active in both
CDMA and FM modes. The output can be used in a single-ended con-
figuration by leaving one of the two pins unconnected, however half the
output voltage will be lost. Each pin should be loaded with 2.5kΩ. The
balanced load should be 5kΩ. The single-ended output impedance is
1.2kΩ, while the balanced output impedance is 2.4kΩ.
VCC
VCC
1.2 k
Ω
1.2 kΩ
I OUT+
I OUT-
Same as pin 21, except complementary output.
See pin 22.
22
23
I OUT-
GC
Analog Gain Control for AGC Amplifiers. The valid control range is from
BIAS
0.5 to 2.5V . These voltages are valid for ONLY a 37kΩ source
DC
impedance. The gain range for the AGC is 95dB.
21 k
40 k
Ω
Ω
GC
7-4
Rev A14 010622