APPLICATION NOTE 335

Maxim Wireless/RF Power Amplifier Selector Guide


Abstract: An overview of Maxim's RF power amplifier (PA) products targeted towards cellular, PCS, 802.11a/b/g, cordless phone and Bluetooth applications. Table compares operating voltage, supply current, output power, package, power added efficiency, and features of Maxim PA ICs. Another table assists selection by market application.

Additional Information: Maxim's RF power amplifiers (PAs) address both linear-modulation formats, such as QAM and QPSK, and nonlinear modulation, such as FM and FSK. PAs designed for the TDMA markets have improved performance features like auto-ramping to reduce spectral splatter. Auto-ramping helps keep a steady VCC and reduce VCO pulling. Automatic thermal protection is available to temporarily reduce output power yielding a very robust PA. PAs for the CDMA markets have been optimized to achieve the lowest current draw in the most probable operating output power levels for urban and suburban CDMA environments. CDMA PAs spend most of their time in the lower output power settings.

For 2.4GHz ISM applications such as 802.11b WLAN, Bluetooth, HomeRF, and cordless phones, Maxim provides low-cost, ultra-small power amplifiers in the ultra-chip scale package. These PAs feature analog or digital power control, closed-loop power control, dynamic bias control, integrated detector, and high efficiency performance.

These are some of the key advantages offered by silicon bipolar RF power amplifiers:
  1. Lower cost, due to higher die yield and simple device fabrication (compared to Heterojunction devices)
  2. Small solution size due to the ultra-chip scale package and minimal external components
  3. No negative bias supply required, such as for many GaAs amplifiers
  4. Robust device performance over temperature and load variations
  5. Auto-ramping feature
The table below shows a sampling of our power amplifiers and their capabilities to date. Note that several of these PAs have been re-tuned to specific performance characteristics and at center frequencies other than as shown.

Table 1. Selector Guide: A Sampling
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) (802.11b)
+17dBm and 3%EVM (802.11g)
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
MAX2840 2.7 to 3.6 120 idle
155 full
5150 to 5350 +15 A 12-UCSP-
1.52x2.02
6% NA High Linear Output Power
+15dBm at 5.25 GHz
(802.11a), 22dB Power
gain, On-chip Power
detector, Simple
input/output matching,
<10uA Shutdown current
MAX2841 2.7 to 3.6 165 idle
260 full
5150 to 5350 +18 A 12-UCSP-
1.52x2.02
7% NA High Linear Output Power
+18dBm at 5.25 GHz
(802.11a), 22dB Power
gain, On-chip Power
detector, Simple
input/output matching,
<10uA Shutdown current

Table 2. Selections by Market
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%
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)
Cellular TDM 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
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
802.11b/g MAX2247 High linear output power, On-chip
power detector, External DAC
controllable Bias, On-chip input
matching
+25dBm Output Power for 802.11b,
+17dBm output power at 3.0% EVM
for 802.11g, 29dB Power Gain
802.11a MAX2840 High linear output power, On-chip
power detector, Simple Matching
External DAC controllable Bias
+15dBm Output Power at 3.9% EVN for
802.11a, 22dBm power gain
MAX2841 High linear output power, On-chip
power detector, Simple Matching
External DAC controllable Bias,
+18dBm Output Power at 3.5% EVN for
802.11a, 22dBm power gain

16-pin PQSOP Package Outline
16/20-pin TSSOP-EP Package Outline
16-pin SO/QSOP Package Outline
8-pin PSOPII Package Outline
9-pin UCSP Package Outline
12-pin UCSP Package Outline
25-pin UCSP Package Outline