Conexant RM912 Datasheet
RM912
CDMA/AMPS 3–4 Volt Power Amplifier (824–849 MHz)
The RM912 dual mode Code Division Multiple Access (CDMA)/Advanced Mobile
Phone Service (AMPS) Power Amplifier is a fully matched 6-pin LCC surface mount
module designed for mobile units operating in the 824-849 MHz cellular bandwidth.
This device meets stringent IS95 CDMA linearity requirements to beyond 28 dBm
output power and can be driven to power output levels beyond 31 dBm for high
efficiency FM mode operation. A single GaAs Microwave Monolithic Intergrated
Circuit (MMIC) contains all active circuitry in the module. The MMIC contains
on-board bias circuitry, as well as input and interstage matching circuits. The output
match is realized off-chip within the module package to optimize efficiency and power
performance into a 50
process that provides for all positive voltage DC supply operation while maintaining
high efficiency and good linearity. Primary bias to the RM912 can be supplied directly
from a three cell nickel-cadmium, single cell lithium-ion, or other suitable battery with
output in the 3-4 volt range. Power down is accomplished by setting the voltage on
the low current reference pin to zero volts. No external supply side switch is needed
as typical “off” leakage is a few microamperes with full primary voltage supplied from
the battery.
Ω load. This device is manufactured with Conexant’s GaAs HBT
Functional Block Diagram
VREF
(3)
VCC1
(1) (4)
VCC2
Distinguishing Features
• Low voltage positive bias supply
• Good linearity
• High efficiency
• Dual mode operation
• Large dynamic range
• 6-pin LCC package
(6 x 6 x 1.5 mm)
• Power down control
Applications
• Digital cellular (CDMA)
• Analog cellular (AMPS)
• Wireless local loop
Driver
Stage Bias
RF
Input
(2) (5)
Data Sheet 100635G
2000, Conexant Systems, Inc. All Rights Reserved. August 2000
Input
Match
DA
GND GND
(6, 7)
MMIC
Power
Stage Bias
Inter
Stage
Match
PA
(6, 7)
Output
Match
MODULE
RF
Output
Electrical Specifications RM912
CDMA/AMPS 3–4 Volt Power Amplifier (824–849 MHz)
Electrical Specifications
The following tables list the electrical characteristics of the RM912 Power Amplifier. Table 1 lists
the absolute maximum rating for continuous operation. Table 2 lists the recommended operating
conditions for achieving the electrical performance listed in Table 3. Tab l e 3 lists the electrical
performance of the RM912 Power Amplifier over the recommended operating conditions.
Table 1. Absolute Maximum Ratings
Parameter Symbol Min Nominal Max Unit
RF Input Power Pin — 3.0 6.0 dBm
Supply Voltage Vcc — 3.4 5.0 Volts
Reference Voltage Vref — 3.0 3.3 Volts
Case Operating Temperature Tc –30 25 +110 °C
Storage Temperature Tstg –55 — +125 °C
NOTE(S):
(1)
No damage assuming only one parameter is set at limit at a time with all other parameters set at or below nominal value.
Table 2. Recommended Operating Conditions
Parameter Symbol Min Nominal Max Unit
(1)
Supply Voltage Vcc 3.2 3.4 4.2 Volts
Reference Voltage Vref 2.9 3.0 3.1 Volts
Operating Frequency Fo 824.0 836.5 849.0 MHz
Operating Temperature To –30 +25 +85 °C
2 Conexant 100635G
RM912 Electrical Specifications
CDMA/AMPS 3–4 Volt Power Amplifier (824–849 MHz)
Table 3. Electrical Specifications for CDMA / AMPS Nominal Operating Conditions
Characteristics Condition Symbol Min Typical Max Unit
Quiescent current Vref = 3.0
Vref = 2.9
Gain–Digital Po = 0 dBm
Po = 28 dBm
Gain–Analog Po = 0 dBm
Po = 31 dBm
Iq
Iq
G
G
G
Gp
—
—
26.0
p
27.0
26.0
26.0
100.0
80.0
28.0
29.0
28.0
28.0
Power Added Efficiency
– Analog Mode
– Digital Mode
Adjacent Channel Power
– 885 kHz Offset
–1980 kHz Offset
(2)
Po = 31 dBm
Po = 28 dBm
Po ≤ 28 dBm
Po ≤ 28 dBm
PA Ea
PA Ed
ACP1
ACP2
43.0
32.0
—
—
45.0
34.0
–50.0
–58.0
Harmonic Suppression
– Second
– Third
Po ≤ 31 dBm
Po ≤ 31 dBm
AFo2
AFo3
—
—
–42.0
–45.0
(1)
—
—
—
—
—
—
—
—
–48.0
–56.0
–30.0
–30.0
mA
mA
dB
dB
dB
dB
%
%
dBc
dBc
dBc
dBc
Noise Power in RX Band
Po @ 28 dBm RxBN —–134.0 –133.0 dBm/Hz
869-894 MHz
Noise Figure — NF — 6.0 — dB
Input Voltage Standing Wave
— VSWR — 1.4:1 ——
Ratio
Stability (Spurious output) 5:1 VSWR
S ——–60.0 dBc
All phases
Ruggedness – No damage Po ≤ 31 dBm Ru 10:1 ——VSWR
NOTE(S):
(1)
Vcc = +3.4 V, Vref = +3.0 V, Freq = 836.5 MHz, Tc = 25 °C, unless otherwise specified.
(2)
ACP is specified per IS95 as the ratio of the total in-band power (1.23 MHz BW) to adjacent power in a 30 kHz BW.
100635G Conexant 3
Electrical Specifications RM912
CDMA/AMPS 3–4 Volt Power Amplifier (824–849 MHz)
Table 4. Electrical Specifications Limits for CDMA / AMPS Recommended Operating Conditions
Characteristics Condition Symbol Min Max Unit
Quiescent current Vref = 3.0 Iq — 140.0 mA
Gain–Digital Po = 0 dBm
Po = 28 dBm
Gain–Analog Po = 0 dBm
Po = 31dBm
Power Added Efficiency
– Analog Mode
– Digital Mode
Adjacent Channel Power
– 885 kHz Offset
–1980 kHz Offset
Harmonic Suppression
Noise Power in RX Band
869—894 MHz
(2)
– Second
– Third
Po = 31 dBm
Po = 28 dBm
Po ≤ 28 dBm
Po ≤ 28 dBm
Po ≤ 31 dBm
Po ≤ 31 dBm
Po @ 28 dBm RxBN —–131.0 dBm/Hz
G
G
p
G
Gp
PAEa
PAEd
ACP1
ACP2
AFo2
AFo3
25.0
25.0
25.0
24.0
42.0
32.0
—
—
—
—
29.0
32.0
29.0
32.0
—
—
–44.0
–56.0
–40.0
–40.0
(1)
dB
dB
dB
dB
%
%
dBc
dBc
dBc
dBc
Input Voltage Standing Wave Ratio — VSWR — 2:1 —
NOTE(S):
(1)
Per Tab le 2 .
(2)
ACP is specified per IS95 as the ratio of the total in-band power (1.23 MHz BW) to adjacent power in a 30 kHz BW.
4 Conexant 100635G
RM912 Characterization Data
CDMA/AMPS 3–4 Volt Power Amplifier (824–849 MHz)
Characterization Data
The following charts illustrate the characteristics of a typical RM912 Power Amplifier tested in the
evaluation board described in the following section. The amplifier was selected by characterizing a
group of devices and choosing a part with average electrical performance at both nominal and
worst case (limit) conditions. Figures 1 through 4 illustrate the digital signal characteristics and
Figures 5 through 8 illustrate the analog characteristics of the RM912.
Figure 1. Digital Gain vs. Output Power
Vref = 3.0V, Vcc = 3.4V
32.50
30.00
27.50
Gain (dB)
25.00
22.50
0.00 5.00 10.00 15.00 20.00 25.00 30.00
Output Power (dBm)
Legend
◆
■
▲
824 MHz @ –30 °C
837 MHz @ –30 °C
849 MHz @ –30 °C
◆
■
▲
100635G Conexant 5
824 MHz @ +25 °C
837 MHz @ +25 °C
849 MHz @ +25 °C
◆
■
▲
824 MHz @ +85 °C
837 MHz @ +85 °C
849 MHz @ +85 °C
Characterization Data RM912
CDMA/AMPS 3–4 Volt Power Amplifier (824–849 MHz)
Figure 2. Digital Adjacent Channel Power Magnitude (ACP1) vs. Output Power
Vref = 3.0V, Vcc = 3.4V, 885 kHz Off set
80.00
70.00
60.00
50.00
| ACP1 (dBc) |
40.00
30.00
20.00
0.00 5.00 10.00 15.00 20.00 25.00 30.00
Output Power (dBm)
Figure 3. Digital Adjacent Channel Power Magnitude (ACP2) vs. Output Power
◆
■
▲
Legend
Vr ef = 3.0V , V c c = 3.4V, 1980 kHz Offset
80.00
70.00
60.00
50.00
| ACP2 (dBc) |
40.00
30.00
20.00
0.00 5.00 10.00 15.00 20.00 25.00 30.00
Output Power (dBm)
◆
■
▲
824 MHz @ –30 °C
837 MHz @ –30 °C
849 MHz @ –30 °C
◆
■
▲
824 MHz @ +25 °C
837 MHz @ +25 °C
849 MHz @ +25 °C
824 MHz @ +85 °C
837 MHz @ +85 °C
849 MHz @ +85 °C
6 Conexant 100635G
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