RMPA1765(2005) Ver la hoja de datos (PDF) - Fairchild Semiconductor
Número de pieza
componentes Descripción
Fabricante
RMPA1765
(Rev.:2005)
(Rev.:2005)
Fairchild Semiconductor
RMPA1765 Datasheet PDF : 8 Pages
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Efficiency Improvement Applications
In addition to high-power/low-power bias modes, the efficiency of the PA module can be significantly increased at backed-off RF
power levels by dynamically varying the supply voltage (Vcc) applied to the amplifier. Since mobile handsets and power amplifiers fre-
quently operate at 10-20 dB back-off, or more, from maximum rated linear power, battery life is highly dependent on the DC power
consumed at antenna power levels in the range of 0 to +16dBm. The reduced demand on transmitted RF power allows the PA supply
voltage to be reduced for improved efficiency, while still meeting linearity requirements for CDMA modulation with excellent margin.
High-efficiency DC-DC converters are now available to implement switched-voltage operation.
With the PA module in low-power mode (Vmode = +2.0V) at+16dBm output power and supply voltages reduced from 3.4V nominal
down to 1.2V, power-added efficiency is more than doubled from 9.5 percent to nearly 25 percent (Vcc = 1.2V) while maintaining a
typical ACPR1 of –52dBc and ACPR2 of less than –61dBc. Operation at even lower levels of Vcc supply voltage are possible with a
further restriction on the maximum RF output power.
Recommended Operating Conditions
Parameter
Operating Frequency
Supply Voltage
Reference Voltage
(operating)
(shutdown)
Bias Control Voltage (low-power)
(high-power)
Linear Output Power (high-power)
(low-power)
Case Operating Temperature
Symbol
f
Vcc1, Vcc2
Vref
Vmode
Pout
Tc
Min
1720
3.0
2.7
0
1.8
0
-30
Typical
3.4
2.85
2.0
Max
1780
4.2
3.1
0.5
3.0
0.5
+28
+16
+85
Units
MHz
V
V
V
V
V
dBm
dBm
°C
DC Turn-On Sequence
1) Vcc1 = Vcc2 = 3.4V (typical)
2) Vref = 2.85V (typical)
3) High-Power: Vmode = 0V (Pout > 16 dBm)
Low-Power: Vmode = 2V (Pout < 16 dBm)
RMPA1765 Rev. D
4
www.fairchildsemi.com
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