MAX2244-MAX2246 [MAXIM]
2.5GHz, 22dBm/20dBm Power Amplifiers with Analog Closed-Loop Power Control; 为2.5GHz ，是22dBm / 20dBm的功率放大器，带有模拟量闭环功率控制
| 型号： | MAX2244-MAX2246 |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | 2.5GHz, 22dBm/20dBm Power Amplifiers with Analog Closed-Loop Power Control |
| 文件： | 总14页 (文件大小：312K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-2204; Rev 2; 8/03
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
General Description
Features
The MAX2244/MAX2245/MAX2246 single-supply, low-
voltage power amplifiers (PAs) are designed for 20dBm
Bluetooth™ Class 1 applications in the 2.4GHz to 2.5GHz
band. The MAX2244/MAX2245 deliver a peak output
power of 22dBm with greater than 20dB output-power
control range. The 22dBm output power compensates for
the filter loss between the PA and the antenna, allowing
20dBm to be delivered to the antenna. The MAX2246 pro-
vides a peak output power of 20dBm for a 30% reduction
in supply current.
o 2.4GHz to 2.5GHz Operation
o Accurate Closed-Loop Output Power Control
Over Full Temperature, Supply, and Input Power
Range
o Convenient Analog Power-Control Interface
o 22dBm Peak Output Power (MAX2244/MAX2245)
o 20dBm Peak Output with 30% Reduced Supply
Current (MAX2246)
The PAs integrate a power detector and closed-loop
power-control circuitry to provide nearly constant output
power over the full range of supply voltage, temperature,
and input power level. The voltage at the analog control
input precisely controls the output power level.
o Internal Bandwidth-Limited Power Ramping
o 50Ω Integrated Input Match
o 0.5µA Shutdown Supply Current
The MAX2244/MAX2245/MAX2246 feature a low-current
shutdown mode through a simple logic input. Internal cir-
cuitry automatically controls the ramp-up/down of the
output power level during turn-on and turn-off to meet
Bluetooth spurious emissions requirements.
o Ultra Chip-Scale Package (1.56mm ✕ 1.56mm)
Ordering Information
TEMP
RANGE
BUMP
PACKAGE
TOP
MARK
The devices operate from a 3V to 3.6V single supply.
The MAX2244/MAX2246 have a power-control voltage
range of 0.5V to 2V, and the MAX2245 has a control
voltage range of 0.9V to 2.2V. The devices are pack-
aged in a miniature ultra chip-scale package (UCSP™),
significantly reducing the required board area.
PART
MAX2244EBL-T -40°C to +85°C 9 UCSP*-9
MAX2245EBL-T -40°C to +85°C 9 UCSP*-9
MAX2246EBL-T -40°C to +85°C 9 UCSP*-9
AAP
AAQ
AAY
*UCSP reliability is integrally linked to the user's assembly
methods, circuit board material, and environment. See the
UCSP Reliability Notice in the UCSP Reliability section of this
data sheet for more information.
Applications
Bluetooth Class 1 Radios
802.11 FHSS/HomeRF™ Radios
2.4GHz Cordless Phones
Pin Configuration appears at end of data sheet.
Functional Diagram
V
V
CC1
CC2
C2
A2
SHUTDOWN
BIAS
RFIN/
B1
SHDN
B3
MATCH
MATCH
MATCH
RFOUT
CONTROL
AMP
POWER
DETECTOR
MAX2244
MAX2245
MAX2246
A1
ANALOG
INTERFACE
PC
A3
GND
C3
C1
B2
GND
GND GND
Bluetooth is a trademark of Ericsson Corp.
UCSP is a trademark of Maxim Integrated Products, Inc.
HomeRF is a trademark of The HomeRF Working Group.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
ABSOLUTE MAXIMUM RATINGS
CC1 CC2
RFIN/SHDN, PC to GND.............................-0.3V to (V
RF Input Power (RFIN)....................................................+10dBm
Load Mismatch (VSWR) Without Damage ..............................6:1
V
, V
, RFOUT to GND.................................-0.3V to +6.0V
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature .....................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
+ 0.3V)
CC
(T - 65°C)
A
Continuous Operating Lifetime............10 years x 0.935
(for operating temperature 65°C < T < 85°C)
Continuous Power Dissipation (T = +85°C)
A
A
9-Pin UCSP (derate 8.8mW/°C above T = +85°C).....700mW
A
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
CAUTION! ESD SENSITIVE DEVICE
DC ELECTRICAL CHARACTERISTICS
(Typical Application Circuit, V
= 3V to 3.6V, no RF signals applied, V
≥ 2V, V = 0, T = -40°C to +85°C, unless otherwise
SHDN PC A
CC
noted. Typical values are at V
= 3V, T = +25°C, unless otherwise noted.) (Note 1)
CC
A
PARAMETER
CONDITIONS
MIN
TYP
65
MAX
3.6
83
UNITS
Supply Voltage
3.0
V
V
V
V
V
V
V
V
V
V
V
V
V
= 0.5V, T = +25°C
A
PC
PC
PC
PC
PC
PC
PC
PC
PC
PC
PC
PC
MAX2244
= 0 to 4dBm,
2.45GHz
= 0.5V, T = -40°C to +85°C
98
A
P
RFIN
= 2V, T = +25°C
172
65
200
205
87
A
= 2V, T = -40°C to +85°C
A
= 0.9V, T = +25°C
A
MAX2245
= 0.9V, T = -40°C to +85°C
93
A
Supply Current (Note 2)
P
RFIN
= 0 to 4dBm,
mA
= 2.2V, T = +25°C
179
42
195
208
55
A
2.45GHz
= 2.2V, T = -40°C to +85°C
A
= 0.5V, T = +25°C
A
MAX2246
= 0.5V, T = -40°C to +85°C
61
A
P
= 0 to 4dBm,
RFIN
= 2V, T = +25°C
118
0.5
140
144
10
A
2.45GHz
= 2V, T = -40°C to +85°C
A
Shutdown Supply Current
SHDN Input Voltage High
SHDN Input Voltage Low
SHDN Input Current
SHDN = GND
µA
V
2.0
0.6
1
V
-1
µA
MAX2244/MAX2246
MAX2245
0.5
0.9
-15
-20
2.0
2.5
5
PC Input Voltage Range
PC Input Current
Active control range
V
MAX2244/MAX2246, V = 0 to 2.5V
PC
µA
MAX2245, V = 0 to 3V
10
PC
2
_______________________________________________________________________________________
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
AC ELECTRICAL CHARACTERISTICS
(Typical Application Circuit, V
noted. Typical values are at V
= 3V, P
= 0 to 4dBm, f
= 2.45GHz, 50Ω system, V
≥ 2V, T = +25°C, unless otherwise
SHDN A
CC
CC
RFIN
RFIN
RFIN
= 3V, P
= 2dBm, f
= 2.45GHz, T = +25°C, unless otherwise noted.)
RFIN A
PARAMETER
Frequency Range (Note 3)
Input Power
CONDITIONS
MIN
2.4
0
TYP
MAX
2.5
4
UNITS
GHz
dBm
MAX2244, V = 0.5V
T
A
T
A
T
A
T
A
T
A
T
A
T
A
T
A
T
A
= +25°C
0
4
7
PC
= +25°C
20.5
20
22.0
23.5
24
MAX2244, V = 2V
PC
= -40°C to +85°C
= +25°C
MAX2245, V = 0.9V
0
4
7
PC
Output Power (Note 2)
dBm
= +25°C
20.5
20
22.0
23.5
24
MAX2245, V = 2.2V
PC
= -40°C to +85°C
= +25°C
MAX2246, V = 0.5V
-4.5
19
0.5
20
5.5
21
PC
= +25°C
= -40°C to +85°C
MAX2246, V = 2V
PC
17
21
MAX2244/MAX2245
MAX2246
-7
-1
Harmonic Output (Notes 2, 4)
P
V
at any level
RFOUT
dBm
-16
-13
-30
Shutdown Mode Output (Note 2)
≤ 0.6V, P
= 4dBm
RFIN
dBm
dBc
SHDN
Frequency offset = 500kHz
Frequency offset = 1.5MHz
Frequency offset = 2.5MHz
-20
-20
-40
In-Band Spurious (Notes 2, 3, 5)
dBm
dBm
µs
Nonharmonic Spurious Output
(Note 2)
All power levels, load VSWR ≤ 3:1
-30
MAX2244/MAX2246, V steps from 0 to 2V
4
4
PC
Power Ramp Turn-On Time
(Notes 2, 6)
MAX2245/MAX2246, V steps from 0 to 2.5V
PC
MAX2244, V steps from 2V to 0
1.8
1.8
1.5:1
PC
Power Ramp Turn-Off Time
(Notes 2, 7)
µs
MAX2245, V steps from 2.5V to 0
PC
Input VSWR (Note 2)
R = 50Ω, over full P
S
range
RFIN
2:1
Note 1: Limits are 100% production tested at T = +25°C. Limits over the entire operating temperature range are guaranteed by
A
design and characterization, but are not production tested.
Note 2: Guaranteed by design and characterization.
Note 3: Assumes the output is optimally matched to cover the 2.4GHz to 2.5GHz band.
Note 4: Valid for the case in which the output stage is matched with a two-section transmission line, lowpass matching network to
minimize the 2nd and 3rd harmonics, as shown in the Typical Application Circuit.
Note 5: Output measured in a 100kHz RBW. Power on/off duty cycle = 50%. Test signal: GFSK, BT = 0.5, 1 bit/symbol, 1Mbps,
frequency deviation = 175kHz.
Note 6: The total turn-on and settling time required for the PA output power to settle to within 1dB of the final value.
Note 7: The total turn-off time for the PA output power to drop to -10dBm.
_______________________________________________________________________________________
3
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
Typical Operating Characteristics
(Typical Application Circuit, V
= 3V, P
= 2dBm, f
= 2.45GHz, SHDN = V , T = +25°C, unless otherwise noted.)
RFIN CC A
CC
RFIN
MAX2244 SUPPLY CURRENT
vs. POWER CONTROL (V
MAX2244
MAX2244
OUTPUT POWER vs. POWER CONTROL (V
)
OUTPUT POWER vs. POWER CONTROL (V
)
)
PC
PC
PC
200
150
100
50
20
10
20
10
V
= 4V
CC
T
= +85°C
A
T
= +85°C
A
V
= 3V
CC
0
0
T
= +25°C
A
T
= +25°C
= -40°C
A
T
= -40°C
A
-10
-20
-10
-20
T
A
V
= 5.0V
CC
0
0
0.5
1.0
1.5
2.0
2.5
0
0.5
1.0
1.5
(V)
2.0
2.5
0
0.5
1.0
1.5
(V)
2.0
2.5
V
(V)
V
V
PC
PC
PC
MAX2244
OUTPUT POWER vs. INPUT POWER
MAX2244
HARMONIC OUTPUT SPECTRUM
MAX2244
OUTPUT POWER vs. FREQUENCY
25
20
15
10
5
25
20
15
10
5
V
= 2V
PC
V
= 2.0V
= 1.0V
PC
V
= 2V
PC
V
0dBm
PC
V
= 1V
PC
10dB/div
5f
O
f
2f
3f
4f
O
O
O
O
V
= 0.5V
-5
V
= 0.5V
2.42
PC
PC
0
0
-15
-10
0
5
0.1
13
2.40
2.44
2.46
2.48
2.50
FREQUENCY (GHz)
INPUT POWER (dBm)
FREQUENCY (GHz)
MAX2244
FSK MODULATED OUTPUT SPECTRUM
MAX2244
POWER-ON/OFF CHARACTERISTICS
MAX2244-46 toc08
30
20
10
0
V
= 2V
PC
P
RFOUT
5
4
3
2
1
0
0dBm
V
SHDN
10dB/div
V
(V)
SHDN
-10
-20
-30
-40
2.45GHz
0.5MHz/div
TIME (2µs/div)
4
_______________________________________________________________________________________
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
Typical Operating Characteristics (continued)
(Typical Application Circuit, V
= 3V, P
= 2dBm, f
= 2.45GHz, SHDN = V , T = +25°C, unless otherwise noted.)
RFIN CC A
CC
RFIN
MAX2245
MAX2245
MAX2245
OUTPUT POWER vs. POWER CONTROL (V
SUPPLY CURRENT vs. POWER CONTROL (V
)
PC
OUTPUT POWER vs. POWER CONTROL (V
)
)
PC
PC
200
150
100
50
20
20
10
T
= +85°C
A
V
= 4V
CC
V
= 5V
CC
10
0
V
= 3V
CC
T
= +25°C
A
T
= +85°C
A
0
T
= -40°C
A
T
= +25°C
-10
-20
-10
-20
A
T
= -40°C
A
0
0
0.5
1.0
1.5
(V)
2.0
2.5
3.0
0
0.5
1.0
1.5
2.0
2.5
3.0
0
0.5
1.0
1.5
(V)
2.0
2.5
3.0
V
PC
V
(V)
V
PC
PC
MAX2245
OUTPUT POWER vs. FREQUENCY
MAX2245
OUTPUT POWER vs. INPUT POWER
MAX2245
HARMONIC OUTPUT SPECTRUM
25
20
15
10
5
25
20
15
10
5
V
V
= 2.5V
= 1.5V
V
PC
= 2.2V
PC
V
= 2.5V
PC
PC
V
= 1.5V
PC
0dBm
10dB/div
5f
O
f
2f
3f
4f
O
O
O
O
V
= 1V
2.42
PC
V
= 1V
-5
PC
0
0
2.40
2.44
2.46
2.48
2.50
0.1
13
-15
-10
0
5
FREQUENCY (GHz)
FREQUENCY (GHz)
INPUT POWER (dBm)
MAX2245
FSK MODULATED OUTPUT SPECTRUM
SHUTDOWN CURRENT vs. TEMPERATURE
800
600
400
200
0
V
= 2.2V
PC
0dBm
10dB/div
2.45GHz
0.5MHz/div
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
_______________________________________________________________________________________
5
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
Typical Operating Characteristics (continued)
(Typical Application Circuit, V
= 3V, P
= 2dBm, f
= 2.45GHz, SHDN = V , T = +25°C, unless otherwise noted.)
RFIN CC A
CC
RFIN
MAX2246
MAX2246
OUTPUT POWER vs. POWER CONTROL (V
MAX2246 SUPPLY CURRENT
vs. POWER CONTROL (V
OUTPUT POWER vs. POWER CONTROL (V
)
)
)
PC
PC
PC
200
150
100
50
20
10
20
T
= +85°C
A
V
= 5V
V
= 4V
CC
CC
10
0
V
= 3V
CC
T
= +85°C
A
0
T
= +25°C
A
-10
-20
-10
-20
T
= +25°C
A
T
= -40°C
A
T
= -40°C
A
0
0
0.5
1.0
1.5
(V)
2.0
2.5
0
0.5
1.0
1.5
(V)
2.0
2.5
0
0.5
1.0
1.5
(V)
2.0
2.5
V
V
V
PC
PC
PC
MAX2246
OUTPUT POWER vs. FREQUENCY
MAX2246
OUTPUT POWER vs. INPUT POWER
MAX2246
HARMONIC OUTPUT SPECTRUM
25
20
15
10
5
25
20
15
10
5
V
= 2V
PC
V
V
= 2V
= 1V
PC
PC
V
= 2V
PC
0dBm
V
= 1V
PC
10dB/div
5f
O
f
2f
3f
4f
O
O
O
O
V
= 0.5V
2.42
V
= 0.5V
-5
PC
PC
0
0
2.40
2.44
2.46
2.48
2.50
-15
-10
0
5
0.1
13
FREQUENCY (GHz)
FREQUENCY (GHz)
INPUT POWER (dBm)
MAX2246
FSK MODULATED OUTPUT SPECTRUM
S11 OF RFIN
0
-5
V
= 2V
PC
1: -20.322dB AT 2.4GHz
2: -13.482dB AT 2.5GHz
0dBm
2
-10
-15
-20
-25
-30
10dB/div
1
2.45GHz
0.5MHz/div
2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0
FREQUENCY (GHz)
6
_______________________________________________________________________________________
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
Pin Description
PIN
NAME
DESCRIPTION
Power-Control Voltage Input. Adjust PC between 0.5V and 2V (MAX2244/MAX2246) or 0.9V to
2.2V (MAX2245) to adjust output power. Drive PC below 0.3V to shut down the control loop
and put the device in standby mode.
A1
PC
A2
V
DC Supply-Voltage Connection for the 2nd Stage
CC2
Ground Connection. Connect to the PC board ground plane. Provide inductance connection
as low as is practical to the ground plane.
A3, B2, C1, C3
GND
RFIN/SHDN
RFOUT
RF Input and Digital Shutdown Control Input. RF path internally DC-blocked and matched to
50Ω. Digital shutdown path is connected to the bias circuitry through a resistor.
B1
PA Open-Collector Output. Requires external pullup inductance for V
matching network for optimum output power and efficiency.
bias and external
CC
B3
C2
V
DC Supply-Voltage Connection for the 1st Stage, Bias, and Control Circuitry
CC1
Detailed Description
Applications Information
The MAX2244/MAX2245/MAX2246 are nonlinear PAs
guaranteed to operate over a 2.4GHz to 2.5GHz fre-
quency range from a 3V to 3.6V single supply. The
MAX2244/MAX2245 provide 22dBm output power, and
the MAX2246 provides 20dBm output power at the
highest power setting. The signal path consists of three
amplifier stages: an input amplifier stage with
adjustable gain, and two fixed-gain amplifier stages.
Power-Supply Connections
The MAX2244/MAX2245/MAX2246 are designed to oper-
ate from a single, positive supply voltage (V ) with three
CC
connections made to V : V
, V
, and RFOUT bias.
traces together using a star layout, which
CC CC1 CC2
Join the V
CC
reduces crosstalk and promotes stable operation. At the
common point of the star, connect 10µF and 10nF de-
coupling capacitors to ground to reduce noise and handle
current transients. Additionally, each leg requires a high-
frequency bypass capacitor and a 1nF power-supply
decoupling capacitor near the IC.
The PAs have a dual-function input (RFIN/SHDN) for
the RF input signal and shutdown control. The shut-
down function is controlled with CMOS level signals,
with a logic low putting the PA into low-current shut-
down. The RF input is internally matched to 50Ω, elimi-
nating the need for external matching.
High-frequency bypass capacitors are required close
to the IC. For V
, connect a capacitor approximately
pad. The distance of the capacitor
CC1
1mm from the V
CC1
The MAX2244/MAX2245/MAX2246 have interstage
matching to optimize output power and efficiency. The last
amplifier stage is open collector using an external pullup
inductor or RF choke. The output match for the PAs also
acts as a lowpass filter that attenuates harmonics.
from the pad affects the impedance at V
, which
CC1
affects output power of the first stage. For optimal out-
put power from stage 1, V
inductance.
requires 0.3nH to 0.4nH
CC1
The output power of the second stage is affected by the
impedance presented to V , which is controlled by
These PAs provide closed-loop power control to pro-
vide a stable output power with variations in tempera-
ture, V , and RF input power. The control amplifier
CC
CC2
the distance between the V
pad and its bypass
CC2
capacitor. For optimal electrical distance, see Figure 1
and Table 1.
varies the gain of the first stage to equalize the power-
control voltage and the internal power-detector output.
The MAX2244/MAX2246 have a 0.5V to 2V power-con-
trol voltage range, and the MAX2245 has a 0.9V to 2.2V
power-control voltage range.
The internal bias circuit provides separate bias volt-
ages and currents to the amplifier stages. An internal
lowpass RC filter isolates the bias currents, preventing
them from being corrupted by the RF signals. The bias
circuit design also ensures the stability of the PA when
connected to high VSWR loads over all power levels.
RFOUT must be pulled up to V
through an inductor
CC
or an inductive transmission line. If using a transmission
line, a high-frequency bypass capacitor from V to
CC
ground is necessary to terminate the transmission line
and set its electrical length. The inductance formed by
the length of the transmission line is part of the output-
matching network, and therefore is critical. See the
Output Matching section for more information on
RFOUT requirements.
_______________________________________________________________________________________
7
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
V
CC
C1
10µF
C2
10nF
C4
27pF
C3
1nF
TRANSCEIVER IC
DAC
T4
T1
V
PC
A1
GND
A3
R2
CC2
A2
2.5kΩ
C11
1nF
C10
RFIN/
SHDN
GND
B2
RFOUT
B3
C6
T2
B1
RFOUT
RFIN
C5
10pF
R2
1kΩ
C7
GND
C1
V
GND
C3
CC1
C2
SHDN
MAX2244
MAX2245
MAX2246
T3
C9
1nF
C8
Figure 1. MAX2244/MAX2245/MAX2246 Typical Application Circuit
Table 1. Typical Application Circuit
Component Values
Place the 1nF power-supply decoupling capacitors
between the star connection and the smaller bypass
capacitors and close to the IC. Larger trace lengths
between the decoupling capacitors and the IC increase
the parasitic trace inductance, which, when combined
COMPONENT
MAX2244
10pF
MAX2245
5.6pF
MAX2246
10pF
C6
C7
C8
C10
T1
with the capacitors on V
and V
, can form an LC
CC2
CC1
1.2pF
1.2pF
1.3pF
tank and introduce instability in the MHz range. If this
happens, you can add a small-value resistor (~10Ω),
between the 1nF capacitor and ground to de-Q the
capacitor and dampen the oscillation.
5pF
5pF
27pF
100pF
100pF
27pF
50Ω, 17.6°
50Ω, 50°
50Ω, 5.3°
50Ω, 5.3°
50Ω, 18°
50Ω, 53°
50Ω, 5.3°
50Ω, 5.9°
50Ω, 25°
50Ω, 50°
50Ω, 5.3°
50Ω, 8.9°
T2
T3
T4
Note: Electrical lengths given for 2.4GHz.
8
_______________________________________________________________________________________
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
RF Input/SHDN
MATCHING IMPEDANCE FOR RFOUT PIN
RFIN/SHDN is a dual-function input for a 2.4GHz to
SMITH CHART
2.5GHz RF signal and a DC-coupled shutdown function.
The input port is internally matched to 50Ω, making it
simple to interface the PAs to a 50Ω source without
external matching components. The PAs are designed to
amplify input signal levels of 0 to 4dBm and, although
the PAs function for input signals outside this range, out-
put power and efficiency degrade. Note: Ensure that the
RF signal is present at the input when the PA is enabled.
If the RF signal is not present at startup, the PA functions
like any closed-loop control system and automatically
goes into a high-gain state, amplifying and transmitting
noise. Avoid this mode of operation.
MAX2244: 6.26Ω + j13.56Ω AT 2.45GHz
The second function of the RFIN/SHDN is shutdown con-
MAX2245: 6.35Ω + j13.25Ω AT 2.45GHz
trol. A DC voltage at the input port digitally controls the
MAX2246: 5.50Ω + j13.50Ω AT 2.45GHz
on/off state with standard CMOS levels. The PA is in low-
current shutdown when the DC voltage is a valid logic
low and is active for a valid logic high. Connect the
SHDN signal to the RFIN/SHDN through a 1kΩ resistor.
Connect the RF signal to the RFIN/SHDN with a 10pF
capacitor in series to block any DC from corrupting the
SHDN signal.
Figure 2. Impedance of Matching Network at RFOUT Pin
Table 2. Matching Network Impedance
MAX2244
MAX2245
MAX2246
FREQUENCY
GHz
REAL IMAG REAL IMAG REAL IMAG
(Ω)
(Ω)
13.2
13.5
13.9
(Ω)
(Ω)
(Ω)
(Ω)
Output Matching
The output structure of these nonlinear PAs is an open-
collector transistor that requires external impedance
matching and pullup inductance for biasing. The recom-
mended output matching network is shown in the Typical
Application Circuits (Figure 1). The impedance presented
to the RFOUT pin is shown in Figure 2 and Table 2. This
impedance is specified relative to a reference plane at
the amplifier output into the matching network and load.
2.40
2.45
2.50
6.47
6.26
6.06
6.61 12.94 5.73 13.01
6.35 13.25 5.50 13.50
6.11 13.59 5.27 14.02
Analog Power Control (PC)
The PAs use a closed-loop power-control system for
consistent output power across input power, supply volt-
age, and temperature. Output power is internally moni-
tored and compared to the desired setting on PC. The
control amplifier then adjusts the first-stage variable-gain
amplifier until the output power matches the desired set-
ting. The result is that the output power is controlled by
the voltage applied to PC.
The matching network is for impedance transformation
that transforms 6Ω to 50Ω with the specified maximum
output power. The network also forms a lowpass filter that
provides attenuation for the 2nd and 3rd harmonics. A
shunt capacitor (C7) is needed to perform the transforma-
tion, and the inductive 50Ω transmission line (T2) is need-
ed to match that capacitance. A larger capacitor can be
used to increase the maximum output power, but the
transmission line also must be increased to maintain a
match with C7. A DC-blocking capacitor (C6) of 5pF to
10pF is necessary between the PA output and the trans-
mission line.
The power-control voltage range at PC for the
MAX2244/MAX2246 is 0 to 2V. Output power remains at
its minimum for V
between 0 and 0.4V. At approxi-
PC
mately 0.4V, output power increases exponentially until
= 2V, where output power is 22dBm (MAX2244) or
V
PC
20dBm (MAX2246). See Figures 3a and 3c for the rela-
tionship between V
and output power for the
PC
The pullup inductance from RFOUT to V
serves three
CC
MAX2244 and MAX2246, respectively.
main purposes: it resonates out the capacitive PA output,
provides biasing for the output stage, and becomes a
high-frequency choke to reduce RF energy from coupling
Likewise, the MAX2245 output power is controlled by
V
, but with a different power-control range. The power-
PC
into V . The pullup inductance normally is a 50Ω trans-
CC
control voltage range of the MAX2245 is 0 to 2.2V, with
output power beginning to increase when V = 0.9V.
mission line (T1); however, chip inductors can be used
instead. The typical application circuit terminates the
transmission line with a capacitor (C6).
PC
Figure 3b shows the V
for the MAX2245.
and output power relationship
PC
_______________________________________________________________________________________
9
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
MAX2244 TYPICAL OUTPUT POWER
P
vs. V
OUT
PC
25
20
15
10
5
0
-5
-10
-15
-20
0
0.50
1.00
1.50
2.00
2.50
V
(V)
PC
P
P
P
P
P
OUT
(dBm)
OUT
OUT
OUT
OUT
V
(V)
V
(V)
PC
V
(V)
V
(V)
V
(V)
PC
PC
PC
PC
(dBm)
(dBm)
(dBm)
(dBm)
0
-9.45
-9.45
-9.45
-9.50
-9.55
-10.79
-15.60
-8.65
-5.41
0.42
0.43
0.44
0.45
0.46
0.47
0.48
0.50
0.52
-3.24
-1.85
-0.64
0.43
1.24
1.97
2.62
3.79
4.75
0.54
0.56
0.58
0.60
0.65
0.70
0.75
0.80
0.85
5.59
6.35
0.90
0.95
1.00
1.10
1.20
1.30
1.40
1.50
1.60
13.76
14.45
15.10
16.25
17.26
18.16
18.95
19.65
20.26
1.70
1.80
1.90
2.00
2.10
2.20
2.30
2.40
2.50
20.79
21.24
21.63
21.91
22.07
22.08
22.09
22.10
22.11
0.30
0.32
0.36
0.37
0.38
0.39
0.40
0.41
7.04
7.67
9.05
10.22
11.26
12.19
13.01
Figure 3a. MAX2244 Typical Output Power vs. Power-Control Voltage
10 ______________________________________________________________________________________
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
MAX2245 TYPICAL OUTPUT POWER
P
vs. V
OUT
PC
25
20
15
10
5
0
-5
-10
-15
-20
0
0.50
1.00
1.50
2.00
2.50
V
(V)
PC
P
P
P
P
OUT
(dBm)
OUT
OUT
OUT
V
(V)
V
(V)
PC
V
(V)
V
(V)
PC
PC
PC
(dBm)
(dBm)
(dBm)
0
-8.00
-8.00
-8.14
-8.46
-17.51
-8.00
-4.13
-1.90
-0.35
0.90
0.91
0.92
0.93
0.94
0.95
0.96
0.97
0.98
0.91
1.91
2.78
3.50
4.20
4.83
5.39
5.93
6.44
0.99
1.00
1.10
1.20
1.30
1.40
1.50
1.60
1.70
6.90
7.33
1.80
1.90
2.00
2.10
2.20
2.30
2.40
2.50
—
20.27
20.79
21.22
21.59
21.91
22.15
22.20
22.20
—
0.82
0.83
0.84
0.85
0.86
0.87
0.88
0.89
10.64
12.99
14.84
16.33
17.61
18.70
19.59
Figure 3b. MAX2245 Typical Output Power vs. Power-Control Voltage
______________________________________________________________________________________ 11
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
MAX2246 TYPICAL OUTPUT POWER
P
vs. V
OUT
PC
25
20
15
10
5
0
-5
-10
-15
-20
0
0.50
1.00
1.50
2.00
2.50
V
(V)
PC
P
OUT
P
P
P
P
OUT
(dBm)
OUT
OUT
OUT
V
(V)
V
(V)
PC
V
(V)
V
(V)
PC
PC
PC
V
(V)
(dBm)
PC
(dBm)
(dBm)
(dBm)
1.00
1.10
1.20
1.30
1.40
1.50
1.60
1.70
1.80
12.26
13.43
14.60
15.39
16.21
16.97
17.67
18.31
18.93
0
-17.80
-17.80
-17.80
-17.78
-17.65
-17.60
-17.53
-17.44
-17.49
0.40
0.41
0.42
0.43
0.44
0.45
0.46
0.47
0.48
-16.00
-11.80
-8.74
-6.65
-5.02
-3.67
-2.65
-1.78
-1.02
0.49
0.50
0.51
0.52
0.53
0.54
0.55
0.56
0.57
-0.31
0.30
2.75
4.75
6.03
7.26
8.35
9.28
10.89
1.90
2.00
2.10
2.20
2.30
2.40
2.50
—
19.48
19.95
20.33
20.66
20.81
20.82
20.82
—
0.10
0.20
0.30
0.35
0.36
0.37
0.38
0.39
—
—
Figure 3c. MAX2246 Typical Output Power vs. Power-Control Voltage
12 ______________________________________________________________________________________
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
Layout
Marking Information
A good layout is necessary to achieve high-output power
Pin 1 ID
AAA: Product ID Code
with good efficiency. A solid ground plane must be used,
with any free board space also being grounded.
Connect any ground planes using multiple vias and low-
inductance connections. Parasitic inductance reduces
output power and efficiency, so place the ground return
of the chip components as close to the IC as possible.
The MAX2244 EV kit and MAX2246 EV kit PC boards use
via-on-pad for low-inductance connections.
A
X
A
X
A
X
XXX: Lot Code
UCSP Reliability
The UCSP is a unique package that greatly reduces
board space compared to other packages. UCSP relia-
bility is integrally linked to the user’s assembly methods,
circuit board material, and usage environment. Closely
review these areas when considering using a UCSP.
Use a star connection for the power-supply traces that
connect to V , V
CC1 CC2
, and RFOUT. At a common point
of the power-supply traces, connect 10nF and 10µF
decoupling capacitors to ground. Place 1nF capacitors
Performance through Operating Life Test and Moisture
Resistance remains uncompromised as they are primari-
ly determined by the wafer-fabrication process.
Mechanical stress performance is a greater considera-
tion for a UCSP. UCSP solder-joint contact integrity must
be considered because the package is attached through
direct solder contact to the user’s PC board. Testing to
characterize the UCSP reliability performance shows that
it is capable of performing reliably through environmental
stresses. Results of environmental stress tests and addi-
tional usage data and recommendations are detailed in
the UCSP application note, available on Maxim’s web-
site, www.maxim-ic.com.
closer to the IC on each V
trace with the small value
CC
matching capacitors closest to the IC. The distance of
the matching capacitors from the IC is critical. See the
Power Supply Connections section for more information.
The layout of the output section is important because
50Ω traces are used as part of the matching. See the
Output Matching section for component information.
The 50Ω traces can be bent, but be aware of how the
characteristics of the transmission line change, and
compensate for them accordingly.
Use a 50Ω line to directly connect to the input. Place
one pad of the 1kΩ resistor for the SHDN signal directly
on the 50Ω line or as close to the line as possible. Any
trace connected to the 50Ω line changes the line’s
characteristic impedance, causing power loss. The lay-
out of the trace connecting PC is noncritical.
Users should also be aware that, as with any intercon-
nect system there are electromigration-based current
limits that, in this case, apply to the maximum allowable
current in the bumps. Reliability is a function of this cur-
rent, the duty cycle, lifetime, and bump temperature. See
the Absolute Maximum Ratings section for any specific
limitations, listed under Continuous Operating Lifetime.
The chip-scale IC package uses a bump pitch of 0.5mm
(19.7 mil) and a bump diameter of 0.3mm (~12 mil).
Therefore, lay out the solder pad spacing on 0.5mm
(19.7 mil) centers. Use a pad size of 0.25mm (~10 mil)
and a solder mask opening of 0.33mm (13 mil). Round
or square pads are permissible. Refer to the Maxim
document, Wafer Level Ultra-Chipscale Packaging, for
detailed information on UCSP layout and handling.
Chip Information
TRANSISTOR COUNT: 727
PROCESS: Bipolar
Pin Configuration
TOP VIEW
(BUMPS AT THE BOTTOM)
Prototype Chip Installation
Alignment keys on the PC board around the chip are
helpful in prototype assembly. The MAX2244 and
MAX2246 EV kit PC boards have L-shaped alignment
keys at the diagonal corners of the chip. Align the chip
on the board before any other components are placed,
and place the board on a hotplate or hot surface until
the solder starts melting. Remove the board from the
hotplate without disturbing the position of the chip. Let
it cool to room temperature before further processing
the board.
1
2
3
PC
A1
V
GND
CC2
A2
A
A3
RFIN/
SHDN
GND
B2
RFOUT
B3
B
B1
V
GND
C1
CC1
GND
C3
C
C2
UCSP
______________________________________________________________________________________ 13
2.5GHz, 22dBm/20dBm Power Amplifiers with
Analog Closed-Loop Power Control
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
PACKAGE OUTLINE, 3x3 UCSP
1
21-0093
I
1
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
14 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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