RMPA1959 Fairchild Semiconductor, RMPA1959 Datasheet - Page 7

• Manufacturer Part Number: RMPA1959
• Description: IC MOD RF POWER AMP 10PIN 4X4LCC
• Manufacturer: Fairchild Semiconductor
• Type: Power Amplifierr

Specifications of RMPA1959

• Current - Supply: 50mA
• Frequency: 1.85GHz ~ 1.91GHz
• Gain: 23dB ~ 25dB
• Noise Figure: 4dB
• Package / Case: 11-LCC
• Rf Type: CDMA, CDMA2000, PCS
• Voltage - Supply: 3V ~ 4.2V
• Number Of Channels: 1
• Frequency (max): 1.91GHz
• Output Power: 28@1880MHzdBm
• Power Supply Requirement: Single
• Single Supply Voltage (min): 3V
• Single Supply Voltage (typ): 3.4V
• Single Supply Voltage (max): 4.2V
• Package Type: PLCC
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (typ): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Operating Temperature Classification: Commercial
• Operating Temp Range: -30C to 85C
• Pin Count: 10
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• P1db: -
• Test Frequency: -
• Lead Free Status / Rohs Status: Compliant
• Other names: RMPA1959TR

©2004 Fairchild Semiconductor Corporation
Efficiency Improvement Application
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 frequently 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 +16 dBm. 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.
-40
-42
-44
-46
-48
-50
-52
-54
-56
-58
-60
30
29
28
27
26
25
24
23
22
21
20
1840
1840
Vcc=2.0V
Vcc=1.5V
Vcc=1.2V
Vcc=3.4V
1860
1860
RMPA1959 PCS 4x4mm2 PAM
Vref = 2.85V, Pout=16dBm
RMPA1959 PCS 4x4mm2 PAM
Vref = 2.85V, Pout=16dBm
Frequency (MHz)
Frequency (MHz)
1880
1880
Vcc=3.0V
1900
1900
Vcc=1.2V
Vcc=1.5V
Vcc=2.0V
Vcc=3.0V
Vcc=3.4V
1920
1920
The following figures show measured performance of the
PA module in low-power mode (Vmode = +2.0V) at
+16dBm output power and over a range of supply voltages
from 3.4V nominal down to 1.2V. Power-added efficiency is
more than doubled from 10 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. As shown below, the PA module can be
biased at a supply voltage of as low as 0.7V with an
efficiency as high as 10–12 percent at +8dBm output
power. Excellent signal linearity is still maintained even
under this low supply voltage condition.
-55
-57
-59
-61
-63
-65
-67
-69
-71
-73
-75
35
30
25
20
15
10
5
1840
1840
Vcc=3.4V
Vcc=1.5V
Vcc=3.4V
1860
1860
RMPA1959 PCS 4x4mm2 PAM
Vref = 2.85V, Pout=16dBm
RMPA1959 PCS 4x4mm2 PAM
Vref = 2.85V, Pout=16dBm
Frequency (MHz)
Frequency (MHz)
1880
1880
Vcc=3.0V
Vcc=1.2V
Vcc=3.0V
Vcc=1.2V
Vcc=1.5V
Vcc=2.0V
Vcc=2.0V
1900
1900
RMPA1959 Rev. D
1920
1920