Datasheet

MC33411A/B
25
MOTOROLA RF/IF DEVICE DATA
Power Amplifiers
The power amplifiers (Pins 29, 30, 32) are designed to
drive the earpiece in a handset, or the telephone line via a
hybrid circuit in the base unit. Each output (PAO+ and PAO–)
can source and sink 5.0 mA, and can swing 1.3 V
pp
each. For
high impedance loads, each output can swing 2.7 V
pp
(5.4
V
pp
differential). The gain of the amplifiers is set with a
feedback resistor from Pin 30 to 32, and an input resistor at
Pin 32. The differential gain is 2x the resistor ratio. Capacitors
can be used for frequency shaping. The pins’ dc level is VB
(≅1.5 V).
The Mute switch, controlled with bit 6/0, will provide 60 dB
of muting with a 50 kΩ feedback resistor. The amount of
muting will depend on the value of the feedback resistor.
Figures 32 and 33 show the power amplifier
swing/distortion for V
CC
= 3.6 V, and Figure 34 illustrates the
maximum swing capability for various value of V
CC
.
0
3.2
0
PAI (V
pp
)
2.0
1.2
0
2.4 4.4
PAO
–
(
V
)
20
3.5
2.5
PAO– (DISTORTION %)
PAI (V
pp
)
V
CC
(V)
Figure 32. Power Amplifier
Maximum Output Swing
Figure 33. Power Amplifier
Distortion
Figure 34. Power Amplifier
Maximum Output Swing versus V
CC
0.4 0.8 1.2 1.6 2.0 2.8 3.2 3.6 4.0
0.4
0.8
1.6
2.4
2.8
pp
Open
130 Ω
Open
2.4 4.40.4 0.8 1.2 1.6 2.0 2.8 3.2 3.6 4.0
15
10
5.0
0
130 Ω
V
CC
= 3.6 V
T
A
= 25°C
V
CC
= 3.6 V
T
A
= 25°C
PAO
–
(
V
)
pp
3.0
2.5
2.0
1.5
1.0
0.5
0
3.0 3.5 4.0 4.5 5.0 5.5
Open
130 Ω
T
A
= 25°C
ARCHIVE INFORMATION
ARCHIVE INFORMATION
Fr
eescale S
emiconduct
or
, I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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