19-2520; Rev 4; 8/03 2.4GHz SiGe Linear Power Amplifier Features The MAX2247 low-voltage, three-stage linear power amplifier (PA) is optimized for 802.11b/g wireless LAN (WLAN) applications in the 2.4GHz ISM band. The device is integrated with an adjustable bias control, power detector, and shutdown mode. The MAX2247 features 29dB of power gain and delivers up to +24dBm of linear output power at 24% efficiency from a single +3.3V supply. It achieves less than -32dBc firstside lobe suppression and less than -55dBc secondside lobe suppression under 802.11b modulation. In addition, the device can be matched for optimum efficiency and performance at output power levels from +10dBm to +24dBm. Its high +28dBm saturated output power also allows the device to meet the requirements of 802.11g OFDM modulation. ♦ 2.4GHz to 2.5GHz Operating Range The MAX2247 features an external bias-control pin that allows the supply current of the device to be dynamically throttled back at lower output power levels, thus improving efficiency while maintaining sufficient sidelobe suppression. Proprietary internal bias circuitry maintains stable device performance over temperature and voltage-supply variations. An additional power-saving feature is a logic-level shutdown pin that reduces supply current to 0.5µA and eliminates the need for an external supply switch. The integrated shutdown function also allows guaranteed device ramp-on and rampoff times. ♦ +2.7V to +4.2V Single-Supply Operation The MAX2247 integrates a power detector with 20dB dynamic range and ±0.8dB accuracy at the highest output power level. The detector provides a buffered DC voltage proportional to the output power of the device, saving cost and space by eliminating a coupler and op amp usually required to implement a power detector function. The device is packaged in the tiny 3 ✕ 4 chip-scale package (UCSP™), measuring only 1.5mm ✕ 2mm, making it the ideal solution for radios built in small form factors. ♦ Up to +24dBm Linear Output Power (ACPR of Less than -32dBc First-Side Lobe and Less than -55dBc Second-Side Lobe) ♦ 24% PAE at +24dBm Linear Output Power, 3.3V 24% PAE at +21dBm Linear Output Power, 3.0V ♦ 29dB Power Gain ♦ On-Chip Power Detector with Buffered Output ♦ Internal 50Ω Input Matching ♦ External Bias Control for Current Throttleback ♦ Integrated Bias Circuitry ♦ 0.5µA Shutdown Mode ♦ Tiny Chip-Scale Package (1.5mm ✕ 2mm) Ordering Information PART TEMP RANGE PINPACKAGE TOP MARK MAX2247EBC-T -40°C to +85°C 3 x 4 UCSP* AAW *Requires special solder temperature profile in the Absolute Maximum Ratings Sections. Typical Operating Circuit appears at end of data sheet. Pin Configuration TOP VIEW A1 A2 A3 A4 BIAS VCC2 GND2 VCC1 B1 B3 B4 GND3 MAX2247 PD_ OUT GND1 C1 C2 C3 C4 RF_ OUT SHDN VCCB RF_IN Applications IEEE 802.11b DSSS WLAN IEEE 802.11g OFDM WLAN HomeRF™ 2.4GHz Cordless Phones 2.4GHz ISM Radios UCSP is a trademark of Maxim Integrated Products, Inc. HomeRF is a trademark of HomeRF Working Group. ________________________________________________________________ Maxim Integrated Products 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. 1 MAX2247 General Description MAX2247 2.4GHz SiGe Linear Power Amplifier ABSOLUTE MAXIMUM RATINGS VCC1, VCC2, VCCB, RF_OUT to GND....................-0.3V to +4.5V SHDN, BIAS, PD_OUT ................................-0.3V to VCC_ + 0.3V RF Input Power (50Ω source)...........................................+5dBm RF_IN Input Current............................................................±1mA Maximum VSWR Without Damage ........................................10:1 Maximum VSWR for Stable Operation, POUT < +25dBm........5:1 Continuous Power Dissipation (TA = +70°C) 3 ✕ 4 UCSP (derate 28.5mW/°C above +70°C) ..............1.3W Thermal Resistance .........................................................35°C/W Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +125°C Bump Temperature (soldering) (Note 1) Infrared (15s) ...............................................................+220°C Vapor Phase (60s) .......................................................+215°C Continuous Operating Lifetime.....................10yrs × 0.92(TA - 60°C) (For Operating Temperature, TA ≥ +60°C) 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 (MAX2247 EV kit, VCC_ = +2.7V to +4.2V, SHDN = VCC, RF_IN and RF_OUT terminated to 50Ω, TA = -40°C to +85°C. Typical values are at +3V and TA = +25°C, unless otherwise noted.) (Note 2) PARAMETER CONDITIONS TYP MAX UNITS 4.2 V POUT = +24dBm, VCC_ = 3.3V 317 350 POUT = +25dBm, VCC_ = 4.2V 345 Supply Voltage 2.7 Idle current = 250mA with VCC = 3.3V Supply Current (Notes 3, 4) Shutdown Supply Current Digital Input Logic High MIN POUT = +23dBm, VCC_ = 3.0V 305 POUT = +21dBm with optimized output-matching circuit. Refer to the MAX2247 EV kit for details. 175 POUT = +18dBm with optimized output-matching circuit. Refer to the MAX2247 EV kit for details. 120 POUT = +15dBm with optimized output-matching circuit. Refer to the MAX2247 EV kit for details. 85 SHDN = 0, no RF signal applied 0.5 mA 10 2 Digital Input Logic Low µA V 0.8 V Digital Input Current High -1 +5 µA Digital Input Current Low -1 +1 µA 2 _______________________________________________________________________________________ 2.4GHz SiGe Linear Power Amplifier MAX2247 AC ELECTRICAL CHARACTERISTICS (MAX2247 EV kit, VCC_ = +3V, fRF = 2.45GHz, SHDN = VCC, 50Ω RF system impedance, TA = +25°C, unless otherwise noted.) (Note 5) PARAMETER CONDITIONS MIN RF Frequency Range (Notes 4, 6) TA = +25°C 26 TA = -40°C to +85°C 25 VCC_ = 3.3V, POUT = +24dBm 29.5 VCC_ = 4.2V, POUT = +25dBm 30.5 VCC = 3.0V to 3.6V ±0.5 Output Power Over Temperature (Notes 4, 8) ACPR: First-side lobe < -32dBc, second-side lobe < -55dBc PIN = +5dBm Harmonic Output (2f, 3f, 4f) VCC_ = 3V 22 GHz dB dB 23 VCC_ = 3.3V 24 VCC_ = 4.2V 25 dBm 27.8 dBm -45 Input VSWR Over full PIN range Output VSWR Over full POUT range UNITS 29.5 Gain Variation Over Supply Voltage (Note 4) Saturated Output Power MAX 2.4 to 2.5 VCC_ = 3V, POUT = +23dBm Power Gain (Notes 2, 4, 8) TYP dBc 1.8:1 2.5:1 2:1 2.5:1 Power Ramp Turn-On Time (Note 7) 0.8 1.5 µs Power Ramp Turn-Off Time (Note 9) 0.8 1.5 µs RF Output Detector Response Time 0.9 RF Output Detector Voltage (Note 10) POUT = +23dBm 1 POUT = +15dBm 0.6 POUT = +7dBm 0.47 µs V Note 1: This device is constructed using a unique set of packaging techniques that impose a limit on the thermal profile the device can be exposed to during board-level solder attach and rework. This limit permits the use of only the solder profiles recommended in the industry-standard specification, JEDEC 020A, paragraph 7.6, Table 3 for IR/VPR and convection reflow. Preheating is required. Hand or wave soldering is not recommended. Note 2: Characteristics are production tested at TA = +25°C. DC specifications over temperature are guaranteed by design and characterization. Note 3: Idle current is controlled by external DAC for best efficiency over the entire output power range. Note 4: Parameter is measured with RF modulation based on IEEE 802.11b standard. Note 5: Minimum and maximum specifications are guaranteed by design and characterization. Note 6: Operation outside this range is possible but not guaranteed. Note 7: The total turn-on time required for PA output power to settle to within 0.5dB of the final value. Note 8: Specification is corrected for PC board loss of approximately 0.3dB, on the output of the MAX2247 EV kit. Note 9: Total turn-off time required for PA supply current to fall below 10µA. Note 10: See the Typical Operating Characteristics for statistical variation. _______________________________________________________________________________________ 3 2.4GHz SiGe Linear Power Amplifier MAX2247 Typical Operating Characteristics (VCC_ = 3V, fRF = 2.45GHz, with MAX2247 EV kit optimized for POUT = +23dBm. TA = +25°C, unless otherwise noted.) OUTPUT POWER, SUPPLY CURRENT vs. SUPPLY VOLTAGE TA = +85°C TA = +25°C 22 400 TA = -40°C 20 350 18 3.9 400 TA = -40°C 32 29 27 TA = +85°C 26 3.0 3.3 3.6 25 250 4.2 3.9 3.0 2.7 3.3 3.6 3.9 SUPPLY CURRENT vs. SUPPLY VOLTAGE ADJ CPR vs. SUPPLY VOLTAGE ALT CPR vs. SUPPLY VOLTAGE -24 POUT = +23dBm -26 TA = +85°C -46 -48 -30 TA = +25°C -52 TA = +85°C ALT CPR (dBc) 290 TA = +25°C POUT = +23dBm -50 -28 TA = +25°C -32 -34 4.2 MAX2247 toc06 SUPPLY VOLTAGE (V) 300 TA = +85°C -54 -56 -58 -60 280 -36 TA = -40°C -62 -38 260 250 TA = -40°C -66 -40 3.0 3.3 3.6 3.9 4.2 2.7 3.0 SUPPLY VOLTAGE (V) OUTPUT POWER vs. INPUT POWER 2.7 4.2 3.0 3.3 25 VCC = +3.3V 15 VCC = +3.0V BIAS CURRENT ADJUSTED TO KEEP ADJ/ALT CPR = -32dBc/-55dBc 200 150 100 4.2 ADJ/ALT CPR vs. OUTPUT POWER -25 -30 -35 ADJ CPR -40 -45 -50 -55 -60 50 5 3.9 -20 ADJ/ALT CPR (dBc) SUPPLY CURRENT (mA) 250 3.6 SUPPLY VOLTAGE (V) 300 MAX2247 toc07 30 10 3.9 SUPPLY CURRENT vs. OUTPUT POWER VCC = +4.2V 20 3.6 SUPPLY VOLTAGE (V) 40 35 3.3 MAX2247 toc08 2.7 TA = -40°C -64 MAX2247 toc09 270 POUT (dBm) 30 SUPPLY VOLTAGE (V) 310 ALT CPR -65 0 -70 0 -20 -15 -10 -5 PIN (dBm) 4 TA = +25°C 31 28 300 2.7 TA = -40°C 33 ICC 14 250 4.2 POUT = +23dBm 320 20 TA = +85°C POUT = +23dBm SUPPLY VOLTAGE (V) 330 SUPPLY CURRENT (mA) 3.6 TA = +25°C 16 ADJ CPR (dBc) 340 3.3 22 18 MAX2247 toc04 350 3.0 450 350 300 2.7 POUT 24 ICC 16 500 26 MAX2247 toc05 POUT (dBm) 450 POUT 34 MAX2247 toc03 500 26 24 INPUT POWER ADJUSTED TO KEEP ADJ/ALT CPR = -32dBc/-55dBc 28 35 550 GAIN (dB) INPUT POWER ADJUSTED TO KEEP ADJ/ALT CPR = -30dBc/-50dBc GAIN vs. SUPPLY VOLTAGE MAX2247 toc02 550 POUT (dBm) 28 MAX2247 toc01 SUPPLY CURRENT (mA) 30 SUPPLY CURRENT (mA) OUTPUT POWER, SUPPLY CURRENT vs. SUPPLY VOLTAGE 0 5 10 12 14 16 18 20 22 10 12 14 POUT (dBm) _______________________________________________________________________________________ 16 18 POUT (dBm) 20 22 24 2.4GHz SiGe Linear Power Amplifier TA = +85°C SUPPLY CURRENT vs. FREQUENCY POUT = +23dBm -52 ALT CPR (dBc) -31 -32 -33 TA = +25°C -54 TA = +85°C -56 -34 -35 -37 2420 2440 2460 2480 2500 2460 2480 2500 2400 2420 2440 2460 2480 OUTPUT RETURN LOSS -20 -25 INPUT RETURN LOSS -30 TA = +25°C -35 TA = +85°C 1.4 2440 2460 2480 1.0 0.8 0.6 0.4 VCC = +4.2V, TA = -40°C 0 2400 2500 VCC = +2.7V, TA = +85°C 1.2 0.2 -40 2420 MAX2247 toc15 -15 2500 1.6 POWER DETECTOR VOLTAGE (V) 28 MAX2247 toc14 MAX2247 toc13 -10 RETURN LOSS (dB) 2420 2440 2460 2480 2500 0 5 10 15 25 20 FREQUENCY (MHz) FREQUENCY (MHz) POUT (dBm) OUTPUT POWER HISTOGRAM AT FIXED 1V POWER DETECTOR VOLTAGE OUTPUT POWER HISTOGRAM AT FIXED 0.6V POWER DETECTOR VOLTAGE OUTPUT POWER HISTOGRAM AT FIXED 0.47V POWER DETECTOR VOLTAGE SIGMA = 0.237dBm BASED ON 50 PARTS 25 SIGMA = 0.38dBm BASED ON 50 PARTS 20 8 6 4 OCCURRENCES OCCURRENCES 15 10 10 MAX2247 toc18 20 MAX2247 toc16 SIGMA = 0.25dBm BASED ON 50 PARTS MAX2247 toc17 GAIN (dB) 2440 POWER DETECTOR VOLTAGE vs. OUTPUT POWER 20 OCCURRENCES 2420 INPUT/OUTPUT RETURN LOSS vs. FREQUENCY 32 12 260 2400 GAIN vs. FREQUENCY TA = -40°C 14 TA = -40°C FREQUENCY (MHz) 36 16 TA = +25°C 280 FREQUENCY (MHz) POUT = +23dBm 2400 290 FREQUENCY (MHz) 40 24 300 270 -60 2400 TA = +85°C 310 TA = -40°C -58 TA = -40°C -36 POUT = +23dBm SUPPLY CURRENT (mA) TA = +25°C -30 320 MAX2247 toc12 POUT = +23dBm -29 ADJ CPR (dBc) MAX2247 toc10 -28 ALT CPR vs. FREQUENCY -50 MAX2247 toc11 ADJ CPR vs. FREQUENCY -27 15 10 5 5 2 0 0 0 22.625 22.875 23.125 OUTPUT POWER (dBm) 23.375 14.408 14.645 14.882 15.119 15.356 15.593 OUTPUT POWER (dBm) 6.05 6.43 6.81 7.19 7.57 7.95 OUTPUT POWER (dBm) _______________________________________________________________________________________ 5 MAX2247 Typical Operating Characteristics (continued) (VCC_ = 3V, fRF = 2.45GHz, with MAX2247 EV kit optimized for POUT = +23dBm. TA = +25°C, unless otherwise noted.) 2.4GHz SiGe Linear Power Amplifier MAX2247 Pin Description BUMP NAME DESCRIPTION A1 BIAS Bias Control. The overall current is set by the current sourced through the bias pin. See the Bias Circuitry section. A2 VCC2 Second-Stage DC Supply Voltage. Sets the bias and external matching for the second amplifier stage. Requires a small inductance. Bypass to ground using the configuration in the Typical Operating Circuit. A3 GND2 Second-Stage Ground. See the Applications Information section for detailed layout information. A4 VCC1 First-Stage DC Supply Voltage. Sets the bias and external matching for the first amplifier stage. Requires a small inductance. Bypass to ground using the configuration in the Typical Operating Circuit. B1 GND3 B3 PD_OUT Third-Stage Ground. See the Applications Information section for detailed layout information. B4 GND1 C1 RF_OUT C2 SHDN Shutdown Input. Drive logic low to place the device in shutdown mode. Drive logic high for normal operation. C3 VCCB Bias Circuit DC Supply Voltage. Bypass to ground using the configuration in the Typical Operating Circuit. C4 RF_IN RF Input. Internally matched to 50Ω. Requires an external DC-blocking cap. Power-Detector Output. This output is a DC voltage indicating the PA output power. First-Stage and Bias-Control Circuit Ground RF Output. Open-collector output. Requires a pullup inductor, which is part of the matching network. Functional Diagram/Typical Operating Circuit VCC 10nF SHUTDOWN CONTROL TRANSMISSION LINE DAC SHDN BIAS POWER-DETECTOR OUTPUT C5 VCC2 PD_OUT VCC MAX2247 22pF BIAS CIRCUIT 10nF DETECTOR VCCB VCC 3.9nH 10nF VCC1 22pF RF_OUT VCC C4 10nF RF INPUT RF_IN RF OUTPUT INPUT MATCH GND1 22pF C3 GND2 GND3 C33* *NOT REQUIRED FOR OUTPUT POWER LESS THAN +23dBm. REFER TO THE MAX2247 EV KIT FOR LAYOUT AND DESIGN DETAILS. 6 _______________________________________________________________________________________ 2.4GHz SiGe Linear Power Amplifier The MAX2247 linear power amplifier (PA) offers a wide variety of features incorporated into a tiny UCSP package. The device includes internal bias circuitry, an integrated power detector with buffered output, low-power shutdown mode, and internal input matching. The MAX2247 output power can be optimized for +15dBm to +24dBm by adjusting the output, first-stage, and secondstage matching network (see the Typical Operating Circuit) while exceeding 802.11b ACPR requirements. In addition, external bias control allows dynamic throttleback of the supply current to increase efficiency. The MAX2247’s performance can be optimized for lower output power levels. Go to the Maxim website, www.maxim-ic.com, for MAX2247 application notes covering performance at +21dBm, +18dbm, and +15dBm. Bias Circuitry To improve efficiency at lower output levels, a bias pin is offered to allow dynamic current control. An external current DAC or resistor network can be used to throttleback current at lower output powers while still maintaining ACPR requirements. By including an internal voltage regulator along with the bias circuitry, no external bias voltage is necessary. The internal voltage regulator maintains stable performance of the bias circuitry over temperature and supply variations. The overall current of the MAX2247 is set by the current sourced through the bias pin. The overall current is 540 times the bias current. An internal bandgap reference provides +1.2V to each bias stage (see Figure 1). An external resistor to ground can be placed at the bias pin to set the bias current (refer to the MAX2247 evaluation kit). An external current DAC can be connected directly to the bias pin to adjust the bias current of the MAX2247. Figure 2 shows the MAX2247 connected to the MAX2820 zero-IF transceiver, which includes a 4-bit DAC. Shutdown Mode The MAX2247 features a low-power shutdown mode to further reduce current consumption. The MAX2247 responds to logic-level signals at the SHDN pin. A logic-level high enables all circuitry, while a logic-level low places the device in low-power shutdown mode and reduces supply current to 0.5µA (typ). Power-ramp turn-on and turn-off times are guaranteed to be less than 1.5µs. Power Detector This device includes a power detector that samples the peak voltage of the output and generates a voltage proportional to the output power. The detector is fully temperature compensated and allows the user to set the detector bandwidth with an external capacitor. INTERNAL VOLTAGE REFERENCE 1ST-STAGE AMPLIFIER BIAS CURRENT 1.2V 2ND-STAGE AMPLIFIER BIAS CURRENT 1.2V 3RD-STAGE AMPLIFIER BIAS CURRENT 1.2V RF_OUT RF INPUT RF OUTPUT MAX2247 BIAS CONNECTED TO EXTERNAL RESISTOR/DAC FOR SETTING THE BIAS CURRENT Figure 1. Internal Bias Circuitry _______________________________________________________________________________________ 7 MAX2247 Detailed Description MAX2247 2.4GHz SiGe Linear Power Amplifier STANDARD BASEBAND/MAC IC TX POWER DETECTOR MAX2820 RX BASEBAND I/Q ZERO-IF TRANSCEIVER POWER DETECTOR BIAS CIRCUIT CURRENT DAC TX BASEBAND I/Q BALUN RF OUTPUT MAX2247 PA DRIVER SHUTDOWN CONTROL Figure 2. The MAX2247 Connected to the Current DAC of the MAX2820 for Bias Control Applications Information The MAX2247 is a three-stage amplifier that requires special attention to board layout and grounding for optimum output power, gain, efficiency, and side-lobe suppression. For ease of implementation, the MAX2247 evaluation (EV) kit layout should be used as a model. Gerber files are available from Maxim upon request. Follow the recommendations below to optimize performance when adapting the layout to your board. Interstage Matching and Bypassing VCC1 and VCC2 provide DC bias to the open-collector outputs of the first- and second-stage amplifiers and are also part of the interstage matching networks required to optimize performance among the three amplifier stages. The MAX2247 must have a small amount of inductance on the VCC lines in addition to the inductance already provided on-chip. See the Typical Application Circuit for the lumped and discrete component values used on the MAX2247 EV kit for optimum interstage matching and RF bypassing. 8 In addition to RF bypass capacitors on each bias line, a global bypass capacitor of 4.7µF is necessary to filter any noise on the supply line. Route separate VCC bias paths from the global bypass capacitor (using a star topology) to avoid coupling between PA stages. Use the MAX2247 EV kit PC board layout as a guide. Input Matching The MAX2247 includes internal input matching to 50Ω, so no external matching network is required. A DC-blocking capacitor is required at the input to the device. Output Matching The RF_OUT port is an open-collector output that must be pulled to VCC through an RF choke for proper biasing (see the Typical Operating Circuit). A shunt 22pF capacitor to ground is required at the supply side of the inductor. In addition, a matching network is required for optimum gain, efficiency, ACPR, and output power. The EV kit should serve as a good starting point for your layout. However, optimum performance is layout dependent, and some component optimization may be required. It is important to leave room on your board for tuning/optimization. _______________________________________________________________________________________ 2.4GHz SiGe Linear Power Amplifier UCSP Reliability The tiny chip-scale package (UCSP) represents a unique package that greatly reduces board space compared to other packages. UCSP reliability is integrally linked to the user’s assembly methods, circuit board material, and usage environment. Operating life test and moisture resistance remains uncompromised, as it is primarily determined by the wafer-fabrication process. Mechanical stress performance is a greater consideration 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 done to characterize the UCSP reliability performance shows that it is capable of performing reliably through environmental stresses. Users should also be aware that as with any interconnect 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 current, the duty cycle, lifetime, and bump temperature. See the Absolute Maximum Ratings section for any specific limitations listed under Continuous Operating Lifetime. Results of environmental stress tests and additional usage data and recommendations are detailed in the UCSP application note, which can be found on Maxim’s website at www.maxim-ic.com/1st_pages/UCSP.htm. Chip Information TRANSISTOR COUNT: 1425 _______________________________________________________________________________________ 9 MAX2247 Ground Vias To achieve optimum gain, output power, thermal performance, and ACPR performance, ground vias should be properly placed throughout the layout. Each ground pin requires its own through-hole via (diameter = 10mils) placed as near as possible to the device pin. This reduces ground inductance, thermal resistance, and feedback between stages. Use the MAX2247 EV kit PC board layout as a guide. 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.) 12L, UCSP 4x3.EPS MAX2247 2.4GHz SiGe Linear Power Amplifier PACKAGE OUTLINE, 4x3 UCSP 21-0104 F 1 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. 10 ____________________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.