本文概括了Maxim针对蜂窝、PCS、802.11b、无绳电话以及Bluetooth等应用提供的射频(RF)功率放大器(PA)。列出了工作电压、电源电流、输出功率、封装、功效等参数的对照表，并给出了Maxim PA IC的特点。另外，还提供了一个根据市场应用选择的参考表。
Maxim的RF功率放大器即可应用于线性调制，如QAM和QPSK，也可用于非线性调制，如：FM、FSK等。针对TDMA市场设计的PA在性能上有所改进，如：自动斜率控制可减小频谱扩散，自动斜率控制有助于保持Vcc的稳定、降低VCO牵引。自动热保护功能能够根据需要临时减小输出功率，提供一个坚固、耐用的PA。针对CDMA市场推出的PA能够在城市或远郊CDMA环境下、对于大多数便携终端要求的输出功率电平提供更低的电源电流，CDMA PA在大多数时间工作在较低的输出功率状态。
对于2.4GHz ISM应用，如：802.11b WLAN、Bluetooth、HomeRF及无绳电话，Maxim可提供低成本、超小尺寸(如UCSP封装)的功率放大器，这些PA具有模拟或数字的功率控制、闭环功率控制、动态偏置控制、集成检测器等，并具有较高的效率。
以下列出了采用硅双极型工艺设计的RF功率放大器关键特性：
低成本，这一点得益于它较高的管芯产量和简单的器件制作工艺(与超外差器件相比) 小尺寸，采用UCSP封装和较少的外部元件 无需负偏置电源，不同于大多数GaAs放大器 在全温范围和负载变化范围内提供稳定的器件特性 自动斜率控制
下表列出了我们的一些功率放大器及其性能，注意，有几款PA需要在指定的性能参数和中心频点进行重新调谐，与表中参数有差异。
表1. 选择指南: 型号列表
Part Vcc
(V) Icc
(mA) Frequency
(MHz) Pout
(dBm) Class Package PAE
(full) PAE
(derated) Features MAX2235 2.7 to 5.5 20 idle
610 full 800 to 1000 +30.3 C 20-Pin
TSSOP-EP 47% 22%
+24dBm Analog Gain Control, Auto Power Ramp, Shutdown MAX2430 3.0 to 5.5 52 800 to 1000 +21.4 AB 16-Pin
SO/QSOP 24% NA Power Control, Shutdown, Drives MAX2601/02 MAX2601 2.7 to 5.5 450 DC to 1000 +30.0 AB/C 8-Pin
PSOPII 54% 18%
+20dBm Power Transistor MAX2602 2.7 to 5.5 450 DC to 1000 +30.0 AB/C 8-Pin
PSOPII 54% 18%
+20dBm Power Transistor with On-Chip Bias Diode, Power Ramp, Shutdown MAX2264 2.7 to 5.0 34 idle,
58 avg,
95 full 824 to 849 +28.0 AB 16-Pin
TSSOP-EP 32% 12%
+16dBm IS-98 CDMA U.S., Internal Switch,
Smallest, Most Economical Solution MAX2265 2.7 to 5.0 83 full 824 to 849 +28.0 AB 16-Pin
TSSOP-EP 37% 7%
+16dBm IS-98 CDMA U.S., TDMA PAE = 40% at +30dBm MAX2266 2.7 to 5.0 34 idle,
52 avg,
100 full 824 to 849 +28.0 AB 16-Pin
TSSOP-EP 32% 17%
+16dBm IS-98 CDMA U.S., Off-Chip Switch, Lowest Current MAX2267 2.7 to 4.5 34 idle,
56 avg,
95 full 887 to 925 +27.0 AB 16-Pin
TSSOP-EP 28% 12%
+17dBm IS-98 CDMA Japan, Internal Switch,
Smallest, Most Economical Solution MAX2268 2.7 to 4.5 90 idle 887 to 925 +27.0 AB 16-Pin
TSSOP-EP 34% 7%
+13.6dBm IS-98 CDMA Japan, PDC PAE = 41% at +29dBm MAX2269 2.7 to 4.5 34 idle,
50 avg,
100 full 887 to 925 +27.0 AB 16-Pin
TSSOP-EP 29% 17%
+17dBm IS-98 CDMA Japan, Off-Chip Switch, Lowest Current MAX2240 2.7 to 5.0 65 idle
105 full 2400 to 2500 +20 AB UCSP
3x3 30% NA Bluetooth PA with Digital Power Control, Shutdown MAX2242 2.7 to 3.6 280 idle
300 full 2400 to 2500 +22.5 AB UCSP
3x4 17%
Pin=
-7dBm
315mA 6.7%
+13dBm +22.5dBm Output Power at -33dBc ACPR for 802.11b
28.5dB Power Gain
External Bias Control for Current Throttleback
On-Chip Power Detector
Output Power Tunable from +10dBm to +22dBm MAX2244 3.0 to 3.6 65 idle
172 full 2400 to 2500 +22 AB UCSP
3x3 34.2% NA Integrated Input Match
Internal Bandwidth-Limited Power Ramping
Power Control Range: 0.5V to 2.0V
Supply Current = 170mA at +22dBm MAX2245 3.0 to 3.6 65 idle
179 full 2400 to 2500 +22 AB UCSP
3x3 29.2% NA Integrated Input Match
Internal Bandwidth-Limited Power Ramping
Power Control Range: 0.9V to 2.0V
Supply Current = 170mA at +22dBm MAX2246 3.0 to 3.6 42 idle
118 full 2400 to 2500 +20 AB UCSP
3x3 27.8% NA Integrated Input Match
Internal Bandwidth-Limited Power Ramping
Power Control Range: 0.5V to 2.0V MAX2247 2.7 to 3.6 293 idle
390 full 2400 to 2500 +25 AB UCSP
3x4 24.5% 21%
+22.5dBm High Linear Output Power: +25dBm with < -33dBc ACPR
(1st side lobe) and < -55dBc ACPR (2nd side lobe)
25% Efficiency with Linear Output Power
29dB Power Gain
On-Chip Power Detector
External Bias Control for Current Throttleback
On-Chip Input Matching
0.5µA Shutdown Mode MAX2251 2.8 to 4.5 205 idle
1029 full 824 to 849
+32.4
AMPS
+30
TDMA
AB UCSP
3x4
51%
AMPS
41%
TDMA
38%
+30dBm
AMPS Gain: 28dB
Integrated Power Detector
Low-Power Shutdown Mode
PAE: 41% at +30dBm for TDMA
PAE: 51% at +32.4dBm for AMPS MAX2281 2.7 to 4.2 35 idle
731 full 824 to 849 +29 AB UCSP
5x5 +31% 14%
+16dBm PAE: 14% at +16dBm Output Power for CDMA
PAE: 31% at +29dBm Output Power for CDMA
PAE: 40% at +31.5dBm Output Power for AMPS
PAE: 43% at +30.5dBm Output Power for TDMA
Shutdown Mode MAX2282 2.7 to 4.2 35 idle
471 full 887 to 925 +27.5 AB UCSP
5x5 34% 17%
+18dBm PAE: 17% at +18dBm Output Power for JCDMA
PAE: 34% at +27.5dBm Output Power for JCDMA
23dB Low-Power Mode Gain
28dB High-Power Mode Gain
Shutdown Mode MAX2291 2.7 to 4.2 30 idle
629 full 1850 to 1910 +29 AB UCSP
5x5 36% 10%
+15dBm High-Power Path Gain: 27dB
Low-Power Path Gain: 15dB
N-CDMA PAE: 36% at +28dBm
Shutdown Mode
TDMA PAE: 42% at +30.5dBm
W-CDMA PAE: 37% at +28dBm
表2. 针对市场选择
Market Part Advantages Specs Cellular CDMA (U.S.) MAX2265 Low-cost, Simple Layout, Few External Components,
High-peak Efficiency Efficiency = 37% (ACPR = -45)
Efficiency = 35% (ACPR = -48) MAX2264
MAX2266 Low-cost, World''s Lowest Talk Current Talk Current=55mA
16dBm Efficiency =12/18% (2264/66)
Peak Efficiency =32% MAX2281 Small Size Ultra-chip Scale Package
(2.5mm x 2.5mm),
Fixed or Dynamic Biasing PAE: 14% at +16dBm Output Power for CDMA
PAE: 31% at +29dBm Output Power for CDMA
PAE: 40% at +31.5dBm Output Power for AMPS
PAE: 43% at +30.5dBm Output Power for TDMA MAX2251 Small Size Ultra-chip Scale Package
(2.06mm x 2.06mm),
Integrated Power Detector,
Low-power Shutdown Mode Gain: 28dB
PAE: 41% at +30dBm for TDMA
PAE: 51% at +32.4dBm for AMPS CDMA (Japan) MAX2268 Low-cost, Simple Layout, Few External Components,
High-peak Efficiency Efficiency = 37% (ACPR = -45)
Efficiency = 35% (ACPR = -48) MAX2267
MAX2269 Low-cost, World''s Lowest Talk Current Talk Current=55mA
16dBm Efficiency =12/18% (2264/66 and ACPR=-45)
Peak Efficiency =33% (ACPR=-45) MAX2282 Small Size Ultra-chip Scale Package
(2.5mm x 2.5mm) PAE: 17% at +18dBm Output Power for JCDMA
PAE: 34% at +27.5dBm Output Power for JCDMA
23dB Low-Power Mode Gain
28dB High-Power Mode Gain PCS CDMA MAX2291 Small Size Ultra-chip Scale Package
(2.5mm x 2.5mm), Shutdown High-Power Path Gain: 27dB
Low-Power Path Gain: 15dB
N-CDMA PAE: 36% at +28dBm
TDMA PAE: 42% at +30.5dBm
W-CDMA PAE: 37% at +28dBm Cellular TDMA MAX2281 Shutdown Mode PAE: 14% at +16dBm Output Power for CDMA
PAE: 31% at +29dBm Output Power for CDMA
PAE: 40% at +31.5dBm Output Power for AMPS
PAE: 43% at +30.5dBm Output Power for TDMA MAX2251 Small Size Ultra-chip Scale Package
(2.06mm x 2.06mm),
Integrated Power Detector,
Low-power Shutdown Mode Gain: 28dB
PAE: 41% at +30dBm for TDMA PCS TDMA MAX2291 Small Size Ultra-chip Scale Package
(2.5mm x 2.5mm), Shutdown High-Power Path Gain: 27dB
Low-Power Path Gain: 15dB
N-CDMA PAE: 36% at +28dBm
TDMA PAE: 42% at +30.5dBm
W-CDMA PAE: 37% at +28dBm PDC MAX2265 Low-cost, Simple Layout, Few External Components,
High-peak Efficiency Efficiency=40% (ACPR=-28)
Pout=30dBm AMPs MAX2251 Small Size Ultra-chip Scale Package
(2.06mm x 2.06mm),
Integrated Power Detector,
Low-power Shutdown Mode Efficiency=51%
Pout=32.4dBm MAX2265 Low-cost, Simple Layout, Few External Components,
High-peak Efficiency PAE: 48% at +31.5dBm Output Power for AMPS WLL MAX2265 Low-cost, Simple Layout, Few External Components,
High-peak Efficiency Efficiency=37% (ACPR=-45)
Efficiency=35% (ACPR=-48) 900MHz ISM MAX2235 Analog Gain Control, Auto Power Ramp, Shutdown PAE: 47% at +30.3dBm Output Power MAX2251 Small Size Ultra-chip Scale Package
(2.06mm x 2.06mm),
Integrated Power Detector,
Low-power Shutdown Mode Gain: 28dB
PAE: 41% at +30dBm for TDMA
PAE: 51% at +32.4dBm for AMPS Bluetooth
HomeRF
2.4GHz DECT MAX2240 Small Size Ultra-chip Scale Package
(1.56mm x 1.56mm),
2-bit Digital Power Control +20dBm, Efficiency =30% MAX2244 Closed-loop Analog Power Control,
Small Size Ultra-chip Scale Package
(1.56mm x 1.56mm) +22dBm, Efficiency = 34.2%
Power control range 0.5V to 2V MAX2245 Closed-loop Analog Power Control,
Small Size Ultra-chip Scale Package
(1.56mm x 1.56mm) +22dBm, Efficiency = 29.2%
Power control range 0.9V to 2V MAX2246 Closed-loop Analog Power Control,
Small Size Ultra-chip Scale Package
(1.56mm x 1.56mm) +20dBm, Efficiency = 27.8%
Power control range 0.5V to 2V Cellular TDMA/AMPS
Dual Mode MAX2251 Small Size Ultra-chip Scale Package
(2.06mm x 2.06mm),
Integrated Power Detector,
Low-power Shutdown Mode Gain: 28dB
PAE: 41% at +30dBm for TDMA
PAE: 51% at +32.4dBm for AMPS 802.11b WLAN MAX2242 Integrated Power Detector,
Dynamic Bias Control,
Output Power Tunable from +10dBm to +22dBm +22.5dBm Output Power at -33dBc ACPR for 802.11B
28.5dB Power Gain