MMM5063 Freescale Semiconductor, Inc, MMM5063 Datasheet - Page 10

• Manufacturer Part Number: MMM5063
• Description: Rf Power Amplifier
• Manufacturer: Freescale Semiconductor, Inc

Application Information
4 Application Information
4.1 Power Control Considerations
The MMM5063 is designed for open loop (drain control) applications. A PMOS FET is used to switch the
MMM5063 drain and vary the supply voltage from 0 to the battery voltage setting (V
concept schematic (see Figure 22) describes the application circuit used to control the device through the
drain voltage.
A drain control provides a linear transfer function which is repeatable versus control voltage (see
Figure 16).
4.2 GSM Second Harmonic (H2) Trap Circuitry
When transmitting in GSM saturated mode, the second harmonic is naturally present at the RF output of
the PA and reaches the antenna after additional filtering in the front-end. ETSI specifies that harmonic
level cannot exceed -36 dBm. In order to improve H2 rejection in low Band (GSM), an H2 trap has been
developed. The topology is based on a Low Pass π Cell Filter (see Figure 17) where the first shunt
capacitor is actually part of the PA output match.
This circuit reduces H2 level by 7 to 8 dB with low in-band insertion losses (mainly due to the series
inductor). Moreover, this structure can be used to match Power amplifier module output to the
switchplexer.
10
Figure 16. Output Power versus Drain Voltage
Freescale Semiconductor, Inc.
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
For More Information On This Product,
GSM Out
0
0
0402 Murata
MMM5063 Advance Information
2.0
460 pH
Figure 17. Low Pass Filter
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8.2 pF
V
D
2
4.0
, DRAIN VOLTAGE SQUARED (V
Coilcraft
7.5 nH
0603
6.0
8.0
460 pH
2.2 pF
0402 Murata
10
Switchplexer
2
)
12
14
bat
). The simplified
MOTOROLA