19-1912; Rev 0; 1/01 NUAL KIT MA ATION EET H S A EVALU T WS DA O L L O F 2.4GHz to 2.5GHz Linear Power Amplifier ________________________Applications Features ♦ 2.4GHz to 2.5GHz Operating Range ♦ +22.5dBm Linear Output Power (ACPR of <-33dBc 1st-Side Lobe and <-55dbc 2nd-Side Lobe) ♦ 28.5dB Power Gain ♦ On-Chip Power Detector ♦ External Bias Control for Current Throttleback ♦ +2.7V to +3.6V Single-Supply Operation ♦ 0.5µA Shutdown Mode ♦ Tiny Chip-Scale Package (1.5mm ✕ 2.0mm) Ordering Information PART TEMP. RANGE PINPACKAGE TOP MARK MAX2242EBC -40°C to +85°C 3✕4 UCSP AAE Pin Configuration RF_IN GND VCC1 C4 B4 A4 IEEE 802.11b DSSS Radios Wireless LANs HomeRF 2.4GHz Cordless Phones GND 2.4GHz ISM Radios C3 VCCB BIAS CIRCUIT A3 PD_OUT SHDN C2 B2 VCC2 A2 Actual Size DET 1.5mm ✕ 2.0mm Typical Application Circuit appears at end of data sheet. UCSP is a trademark of Maxim Integrated Products, Inc. C1 B1 A1 BIAS RF_OUT GND 3✕4 UCSP ________________________________________________________________ Maxim Integrated Products 1 For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX2242 General Description The MAX2242 low-voltage linear power amplifier (PA) is designed for 2.4GHz ISM-band wireless LAN applications. It delivers +22.5dBm of linear output power with an adjacent-channel power ratio (ACPR) of <-33dBc 1st-side lobe and <-55dBc 2nd-side lobe, compliant with the IEEE 802.11b 11MB/s WLAN standard with at least 3dB margin. The PA is packaged in the tiny 3x4 chip-scale package (UCSP™), measuring only 1.5mm x 2.0mm, ideal for radios built in small PC card and compact flash card form factors. The MAX2242 PA consists of a three-stage PA, power detector, and power management circuitry. The power detector provides over 20dB of dynamic range with ±0.8dB accuracy at the highest output power level. An accurate automatic level control (ALC) function can be easily implemented using this detector circuit. The PA also features an external bias control pin. Through the use of an external DAC, the current can be throttled back at lower output power levels while maintaining sufficient ACPR performance. As a result, the highest possible efficiency is maintained at all power levels. The device operates over a single +2.7V to +3.6V power-supply range. An on-chip shutdown feature reduces operating current to 0.5µA, eliminating the need for an external supply switch. MAX2242 2.4GHz to 2.5GHz Linear Power Amplifier ABSOLUTE MAXIMUM RATINGS VCC1, VCC2 to GND (no RF signal applied) ..........-0.3V to +5.5V RF Input Power ...............................................................+10dBm SHDN, BIAS, PD_OUT, RF_OUT ................-0.3V to (VCC + 0.3V) DC Input Current at RF_IN Port.............................-1mA to +1mA Maximum VSWR Without Damage ........................................10:1 Maximum VSWR for Stable Operation.....................................5:1 Continuous Power Dissipation (TA = +85°C) 3✕4 UCSP (derate 80mW/°C above +85°C) ..................1.6W Operating Temperature Range ...........................-40°C to +85°C Thermal Resistance .........................................................25°C/W Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +125°C Lead Temperature (soldering, 10s) .................................+260°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. DC ELECTRICAL CHARACTERISTICS (VCC = +2.7V to +3.6V, fIN = 2.4GHz to 2.5GHz, V SHDN = VCC, RF_IN = RF_OUT = connected to 50Ω load, TA = -40°C to +85°C. Typical values are measured at VCC = +3.3V, fIN = 2.45GHz, TA = +25°C, unless otherwise noted.) (Note 1) PARAMETER CONDITIONS Supply Voltage Supply Current (Notes 2, 3) Shutdown Supply Current Logic Input Voltage High MIN TYP 2.7 POUT = +22dBm, VCC = +3.3V, idle current = 280mA 300 POUT = +13dBm, idle current = 55mA 90 POUT = +5dBm, idle current = 25mA 50 V SHDN = 0, no RF input 0.5 UNITS 3.6 V 335 mA 10 2.0 Logic Input Voltage Low 2 MAX µA V 0.8 V Logic Input Current High -1 5 µA Logic Input Current Low -1 1 µA _______________________________________________________________________________________ 2.4GHz to 2.5GHz Linear Power Amplifier (MAX2242 Evaluation Kit, VCC = +3.3V, V SHDN = VCC, 50Ω source and load impedance, fIN = 2.45GHz, TA = +25°C, unless otherwise noted.) (Note 6) PARAMETER CONDITIONS Frequency Range (Notes 3, 4) Power Gain (Notes 1, 3) MIN TYP 2.4 TA = +25°C 26.5 TA = -40°C to +85°C 25.5 MAX UNITS 2.5 GHz 28.5 dB Gain Variation Over Temperature (Note 3) TA = -40°C to +85°C ±1.2 dB Gain Variation Over VCC (±10%) (Note 3) VCC = +3.0V to +3.6V ±0.3 dB Output Power (Notes 3, 5, 8) ACPR, 1st-side lobe < -33dBc, 2nd-side lobe < -55dBc 22.5 dBm Saturated Output Power PIN = +5dBm 26.5 dBm -40 dBc Harmonic Output (2f, 3f, 4f) 21.5 Input VSWR Over full PIN range 1.5:1 Output VSWR Over full POUT range 2.5:1 Power Ramp Turn-On Time (Note 7) SHDN from low to high 1 1.5 µs Power Ramp Turn-Off Time (Note 7) SHDN from high to low 1 1.5 µs 2.5 5 µs RF Output Detector Response TIme RF Output Detector Voltage Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: Note 7: Note 8: Note 9: Po = +22dBm (Note 9) 1.8 Po = +13dBm (Note 9) 0.9 Po = +5dBm (Note 9) 0.55 V Specifications over TA = -40°C to +85°C are guaranteed by design. Production tests are performed at TA = +25°C. Idle current is controlled by external DAC for best efficiency over the entire output power range. Parameter measured with RF modulation based on IEEE 802.11b standard. Power gain is guaranteed over this frequency range. Operation outside this range is possible, but is not guaranteed. Output two-tone third-order intercept point (OIP3) is production tested at TA = +25°C. The OIP3 is tested with two signals at f1 = 2.450GHz and f2 = 2.451GHz with PIN = -9dBm. Min/max limits are guaranteed by design and characterization. The total turn-on and turn-off times required for PA output power to settle to within 0.5dB of the final value. Excludes PC board loss of approximately 0.15dB. See Typical Operating Characteristics for statistical variation. _______________________________________________________________________________________ 3 MAX2242 AC ELECTRICAL CHARACTERISTICS Typical Operating Characteristics (VCC = +3.3V, fIN = 2.45MHz, RF modulation = IEEE 802.11b, V SHDN = VCC, TA = +25°C, unless otherwise noted.) PO = +22dBm 320 28 280 TA = -40°C 260 TA = +25°C TA = +85°C TA = +85°C 27 240 IDLE CURRENT SET TO 280mA AT VCC = +3.3V, TA = +25°C 26 220 3.3 3.6 2.7 3.0 SUPPLY VOLTAGE (V) 300 IDLE CURRENT ADJUSTED TO KEEP ACPR/ALT = -33/-55dBc 240 180 TA = +25°C 120 90 TA = +85°C 60 30 0 2 4 6 8 10 12 14 16 18 20 22 5 -32 POUT = +22 dBm -33 TA = -40°C TA = +25°C -34 TA = +85°C -35 17 18 19 20 21 22 23 24 25 2400 2425 2450 2475 2500 FREQUENCY (MHz) ICC vs. FREQUENCY POWER DETECTOR VOLTAGE vs. OUTPUT POWER OUTPUT POWER HISTOGRAM AT FIXED 1.6V POWER DETECTOR VOLTAGE 310 MAX2242 toc07 TA = +25°C TA = +85°C 305 300 295 TA = -40°C 2 VCC = +3.0V, TA = +25°C VCC = +3.3V, TA = +85°C VCC = +3.3V, TA = -40°C VCC = +3.6V, TA = +25°C VCC = +3.3V, TA = +25°C 1.8 1.6 1.4 1.2 1 2425 2450 FREQUENCY (MHz) 2475 2500 25 SIGMA = 0.14dBm BASED ON 100 PARTS 20 15 10 VCC = +2.7V, TA = +25°C 0.4 280 30 0.8 0.6 285 2400 3 OUTPUT POWER (dBm) PO = +22dBm 290 1 OUTPUT POWER (dBm) 320 315 -3 -1 ACPR vs. FREQUENCY IDLE CURRENT = 280mA 16 POWER DETECTOR VOLTAGE (V) 0 -7 -5 MAX2242 toc09 150 -24 -25 -26 -27 -28 -29 -30 -31 -32 -33 -34 -35 -36 -37 -38 -39 -40 OCCURENCES ICC (mA) ACPR (dBc) TA = -40°C 210 -15 -13 -11 -9 INPUT POWER (dBm) MAX2242 toc08 270 3.6 ACPR vs. OUTPUT POWER MAX2242 toc04 ICC vs. OUTPUT POWER 330 3.3 SUPPLY VOLTAGE (V) ACPR (dBc) 3.0 MAX2242 toc05 2.7 4 OUTPUT POWER (dBm) 29 ICC (mA) GAIN (dB) 300 TA = +25°C 28 27 26 25 24 23 22 21 20 19 18 17 16 15 MAX2242 toc03 30 OUTPUT POWER vs. INPUT POWER MAX2242 toc02 TA = -40°C MAX2242 toc01 PO = +22dBm ICC vs. SUPPLY VOLTAGE MAX2242 toc06 GAIN vs. SUPPLY VOLTAGE 31 ICC (mA) MAX2242 2.4GHz to 2.5GHz Linear Power Amplifier 5 0 0 2 4 6 8 10 12 14 16 18 20 22 OUTPUT POWER (dBm) 21.6 21.8 22 22.2 OUTPUT POWER (dBm) _______________________________________________________________________________________ 22.4 p2.4GHz to 2.5GHz Linear Power Amplifier SIGMA = 0.25dBm BASED ON 100 PARTS 20 15 10 10 5 5 0 0 12.1 12.3 12.5 12.7 12.9 13.1 13.3 13.5 13.7 2.8 3.4 4.0 4.6 5.2 5.8 6.4 7.0 OUTPUT POWER (dBm) S11, S22, vs. FREQUENCY MAX2242 S21 vs. FREQUENCY -5 30 PIN = -15dBm 29 S21 (dB) S22 -7 MAX2242 toc13 PIN = -15dBm -3 S11, S22 (dB) 2.2 OUTPUT POWER (dBm) MAX2242 toc12 -1 SIGMA = 0.75dBm BASED ON 100 PARTS 15 OCCURRENCES OCCURRENCES 20 MAX2242 toc10 25 MAX2242 toc11 OUTPUT POWER HISTOGRAM AT FIXED 0.5V POWER DETECTOR VOLTAGE OUTPUT POWER HISTOGRAM AT FIXED 0.8V POWER DETECTOR VOLTAGE 28 27 -9 -11 S11 26 -13 25 -15 2400 2420 2440 2460 FREQUENCY (MHz) 2480 2500 2400 2420 2440 2460 2480 2500 FREQUENCY (MHz) _______________________________________________________________________________________ 5 MAX2242 Typical Operating Characteristics (continued) (VCC = +3.3V, fIN = 2.45MHz, RF modulation = IEEE 802.11b, V SHDN = VCC, TA = +25°C, unless otherwise noted.) 2.4GHz to 2.5GHz Linear Power Amplifier MAX2242 Pin Description PIN NAME FUNCTION A1 GND 3rd Stage Ground. Refer to Application Information section for detailed PC-board layout information. A2 VCC2 2nd Stage Supply Voltage. Bypass to ground using configuration in the typical operating circuit. A3 GND 3rd Stage Ground. Refer to Application Information section for detailed PC-board layout information. A4 VCC1 1st Stage Supply Voltage. Bypass to ground using configuration in the typical operating circuit. B1 RF_OUT RF Output. Requires external matching. B2 PD_OUT Power Detector Output. This output is a DC voltage indicating the PA output power. Connect a 47kΩ resistor to GND. B4 GND 1st Stage and Bias Control Circuit Ground C1 BIAS Bias Control. Connect one 8kΩ resistor from BIAS to GND and one 8kΩ resistor from BIAS to DAC block to set the idle current. 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 configuration in the typical operating circuit. C4 RF_IN RF Input. Requires external matching. Detailed Description The MAX2242 is a linear PA intended for 2.4GHz ISMband wireless LAN applications. The PA is fully characterized in the 2.4GHz to 2.5GHz ISM band. The PA consists of two driver stages and an output stage. The MAX2242 also features an integrated power detector and power shutdown control mode. Dynamic Power Control The MAX2242 is designed to provide optimum poweradded efficiency (PAE) in both high and low power applications. For a +3.3V supply at high output power level, the output power is typically +22.5dBm with an idle current of 280mA. At low output-power levels, the DC current can be reduced by an external DAC to increase PAE while still maintaining sufficient ACPR performance. This is achieved by using external resistors connected to the BIAS pin to set the bias currents of the driver and output stages. The resistors are typically 8kΩ. Typically, a DAC voltage of 1.0V will give a 280mA bias current. Increasing the DAC voltage will decrease the idle current. Similarly, decreasing the DAC voltage will increase the idle current. The BIAS pin is maintained at a constant voltage of 1.0V, allowing the user to set the desired idle current using only two off-chip 1% resistors: a shunt resistor, R2, from BIAS to ground; and a series resistor, R1, to 6 the DAC voltage, as shown in the Typical Application Circuit. Resistor values R1 and R2 are determined as follows: VMAX = 1.0 + (1.0 ✕ R1) / R2; (ICC = 0, VDAC = VMAX) (1) IMAX = (1.0 ✕ 1867) ✕ (R1 + R2) / (R1 ✕ R2); (ICC = IMAX = max value, VDAC = 0) (2) IDAC = (VDAC - 1.0) / R1 (3) IMID = (1.0 ✕ 1867) / R2; (VDAC = 1.0V or floating) (4) ICC = 1867 ✕ IBIAS (5) where VMAX = is the maximum DAC voltage IMAX = is the maximum idle current IMID = is the idle current with VDAC = 1.0V or not connected VDAC = is the DAC voltage IDAC = is the DAC current If no DAC is used and a constant idle current is desired, use equation 4 to determine the resistor values for a given total bias current. Only R2 is required. _______________________________________________________________________________________ 2.4GHz to 2.5GHz Linear Power Amplifier The RFOUT port is an open-collector output that must be pulled to VCC through a 10nH RF choke for proper biasing. A shunt 33pF 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 load impedance seen at the RFOUT port of the MAX2242 on the EV kit is approximately 8 + j5Ω. This should serve as a good starting point for your layout. However, optimum performance is layout dependent and some component optimization may be required. See the Typical Application Circuit for the lumped and discrete component values used on the MAX2242 EV kit to achieve this impedance. Shutdown Mode Placement and type of ground vias are important to achieve optimum gain and output power and ACPR performance. Each ground pin requires its own throughhole via (via diameter = 10mils) placed as near to the device pin as possible to reduce ground inductance and feedback between stages. Use the MAX2242 EV kit PC board layout as a guide. Apply logic low to SHDN (pin C2) to place the MAX2242 into shutdown mode. In this mode, all gain stages are disabled and supply current typically drops to 0.5µA. Note that the shutdown current is lowest when V SHDN = 0. Power Detector The power detector generates a voltage proportional to the output power by monitoring the output power using an internal coupler. It is fully temperature compensated and allows the user to set the bandwidth with an external capacitor. For maximum bandwidth, connect a 47kΩ resistor from PD_OUT to GND and do not use any external capacitor. Applications Information Interstage Matching and Bypassing VCC1 and VCC2 provide bias to the first and second stage amplifiers, and are also part of the interstage matching networks required to optimize performance between the three amplifier stages. See the Typical Application Circuit for the lumped and discrete component values used on the MAX2242 EV kit for optimum interstage matching and RF bypassing. In addition to RF bypass capacitors on each bias line, a global bypass capacitor of 22µF is necessary to filter any noise on the supply line. Route separate V CC bias paths from the global bypass capacitor (star topology) to avoid coupling between PA stages. Use the MAX2242 EV kit PC board layout as a guide. External Matching The RFIN port requires a matching network. The RFIN port impedance is 16–j30 at 2.45GHz. See the Typical Application Circuit for recommended component values. Ground Vias Layout and Thermal Management Issues The MAX2242 EV kit serves as a layout guide. Use controlled-impedance lines on all high-frequency inputs and outputs. The GND pins also serve as heat sinks. Connect all GND pins directly to the topside RF ground. On boards where the ground plane is not on the component side, connect all GND pins to the ground plane with plated multiple throughholes close to the package. PC board traces connecting the GND pins also serve as heat sinks. Make sure that the traces are sufficiently wide. UCSP Reliability UCSP represents a unique packaging form factor that may not perform equally to a packaged product through traditional mechanical reliability tests. UCSP reliability is integrally linked to the user’s assembly methods, circuit-board material, and usage environment. The user should closely review these areas when considering use of a UCSP. Performance through the 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. UCSPs are attached through direct solder contact to the user’s PC board, foregoing the inherent stress relief of a packaged-product lead frame. Solder joint contact integrity must be considered. Testing done to characterize the UCSP reliability performance shows that it is capable of _______________________________________________________________________________________ 7 MAX2242 For a DAC capable of both sourcing and sinking currents, the full voltage range of the DAC (typically from 0 to +3V) can be used. By substituting the desired values of VMAX and IMAX into equations 1 and 2, R1 and R2 can be easily calculated. For a DAC capable of sourcing current only, use equation 4 to determine the value of resistor R2 for the desired maximum current. Use equation 1 to determine the value of resistor R1 for the desired minimum current. For a DAC capable of sinking current only, set resistors R1 and R2 to 0 and connect the DAC directly to the BIAS pin. Use equation 5 to determine the DAC current required for a given ICC. 2.4GHz to 2.5GHz Linear Power Amplifier MAX2242 Typical Application Circuit VCC VCC DET OUT DAC 0.1µF 47kΩ SHDN R1 8kΩ R2 8kΩ VCC2 0.1µF PD_OUT 50Ω BIAS 33pF VCCB VCC BIAS CIRCUIT 33pF DETECTOR 10nH VCC1 VCC 0.1µF 100pF RF_IN 1.8pF 6pF 2.2nH GND GND GND NOTE: REFER TO MAX2242 EV KIT DATA SHEET FOR DETAILED LAYOUT INFORMATION. performing reliably through environmental stresses. 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. Chip Information TRANSISTOR COUNT: 486 8 _______________________________________________________________________________________ RF_OUT 2.4GHz to 2.5GHz Linear Power Amplifier MAX2242 Package Diagram 1.5 0.75 MAX 0.5 B4 A4 C3 B3 NOT USED A3 C2 B2 A2 C1 B1 A1 0.5 2.0 C4 BOTTOM VIEW SIDE VIEW CHIP-SCALE PACKAGE (ALL DIMENSIONS IN mm) _______________________________________________________________________________________ 9 2.4GHz to 2.5GHz Linear Power Amplifier 12L, UCSP 4x3.EPS MAX2242 Package Information Note: MAX2242 does not use bump B3. 10 ______________________________________________________________________________________