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19-2416; Rev 0; 4/02 +14dBm to +20dBm LO Buffers/Splitters with 1dB Variation General Description The MAX9987 and MAX9988 LO buffers/splitters each integrate a passive two-way power splitter with highisolation input and output buffer amplifiers. These buffers are designed to provide the high output (+14dBm to +20dBm) necessary to drive the LO inputs of high-linearity passive mixers, while offering 40dB reverse isolation to prevent LO pulling. The MAX9987 is internally matched for the cellular/GSM bands, and the MAX9988 is matched for the DCS/PCS/UMTS bands. The typical application circuit provides a nominal +17dBm output power with 1dB variation over supply, temperature, and input power. With two optional resistors, the output power can be precision set from +14dBm to +20dBm. The devices offer more than 30dB output-to-output port isolation, and are offered in 5mm 5mm 20-pin QFN packages with exposed paddle. o 1dB Output Power Variation o +14dBm to +20dBm Adjustable Output Power o Two-Way Power Splitting o 40dB Reverse Isolation o More than 30dB Output-to-Output Isolation o Low Output Noise: -170dBc/Hz at +17dBm o 160mA Supply Current at +17dBm o ESD Protection o Isolated PLL Output (+3dBm) Features MAX9987/MAX9988 Applications Cellular/GSM/DCS/PCS/UMTS Base Station Tx/Rx LO Drive Base Station Main and Diversity Channels Coherent Receivers ISM Wireless LAN Wireless Local Loop Local Multipoint Distribution Service Point-to-Point Systems *EP = Exposed paddle MAX9987EGP MAX9988EGP PART Ordering Information TEMP RANGE -40C to 85C -40C to 85C PINPACKAGE 20 QFN-EP* 20 QFN-EP* FREQUENCY RANGE 700MHz to 1100MHz 1500MHz to 2200MHz Typical Operating Circuit and Block Diagram PLL BUFFER TO PLL PRESCALER OUTPLL (+3dBm) OUTPUT AMP (1) OUT1 (+17dBm) RF INPUT (1) MAX9987 MAX9988 IF OUTPUT (1) IN (+7dBm) RF LO INPUT AMP PASSIVE TWO-WAY POWER SPLITTER BIAS OUTPUT AMP (2) BIASIN BIASOUT OUT2 (+17dBm) RF INPUT (2) IF OUTPUT (2) BIAS CONTROL NETWORK ________________________________________________________________ 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. +14dBm to +20dBm LO Buffers/Splitters with 1dB Variation MAX9987/MAX9988 ABSOLUTE MAXIMUM RATINGS VCC1, VCC2, VCC3, VCCREF to GND.................................................-0.3V to +6.0V IN to GND ...................................................-0.3V to (VCC + 0.3V) OUT1, OUT2, OUTPLL to GND ......................................-0.3V to (VCC + 0.3V) REF to GND ......................................................Source/Sink 5mA INBIAS, OUTBIAS, to GND..................................-0.3V to +0.75V PLLBIAS ......................................................................Sink 25mA RF Input Power ...............................................................+20dBm Continuous Power Dissipation (TA = +70C) 5mm 5mm 20-Pin QFN (derate 20mW/C above +70C).............................................................1600mW JA ....................................................................................50C/W Junction Temperature ......................................................+150C Operating Temperature Range ...........................-40C to +85C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C 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--MAX9987 (Typical Application Circuit, VCC = 4.75V to 5.25V, input and outputs terminated in 50, TA = -40C to +85C. Typical specifications are for VCC = 5.0V and TA = +25C.) (Note 1) PARAMETER Supply Voltage SYMBOL VCC Low power setting (see Table 1 for resistor values) Supply Current ICC Nominal power setting (R1, R2, R4, and R5 not installed) High power setting (see Table 1 for resistor values) 139 CONDITIONS MIN 4.75 TYP 5.00 110 155 221 171 mA MAX 5.25 UNITS V DC ELECTRICAL CHARACTERISTICS--MAX9988 (Typical Application Circuit, VCC = 4.75V to 5.25V, input and outputs terminated in 50, TA = -40C to +85C. Typical specifications are for VCC = 5.0V and TA = +25C.) (Note 1) PARAMETER Supply Voltage SYMBOL VCC Low power setting (see Table 1 for resistor values) Supply Current ICC Nominal power setting (R1, R2, R4, and R5 not installed) High power setting (see Table 1 for resistor values) 150 CONDITIONS MIN 4.75 TYP 5.00 120 162 229 175 mA MAX 5.25 UNITS V 2 _______________________________________________________________________________________ +14dBm to +20dBm LO Buffers/Splitters with 1dB Variation AC ELECTRICAL CHARACTERISTICS--MAX9987 (Typical Application Circuit, VCC = 4.75V to 5.25V, 50 environment, +4dBm < PIN < +10dBm, 700MHz < fIN < 1100MHz, TA = -40C to +85C, unless otherwise noted. Typical specifications are for VCC = 5.0V, PIN = +7dBm, fIN = 900MHz, and TA = +25C, unless otherwise noted.) (Note 1) PARAMETER Operating Frequency SYMBOL f CONDITIONS Low power setting, PIN = +4dBm (see Table 1 for resistor values) Nominal power setting, +4dBm < PIN < +10dBm, 4.75V < VCC < 5.25V, -40C < TA < +85C (R1, R2, R4, and R5 not installed) High power setting, PIN = +10dBm (see Table 1 for resistor values) Output Power (PLL Driver) Input VSWR Output VSWR Output-Noise Power Density OUT1 to OUT2 Isolation OUT2 to OUT1 Isolation OUT1 to RFIN Isolation OUT2 to RFIN Isolation POUTPLL VSWRIN VSWROUT PNOISE S23 S32 S12 S13 VCC = 5.0V, 100MHz offset (R1, R2, R4, and R5 not installed) VCC = 5.0V, nominal power setting (R1, R2, R4, and R5 not installed) VCC = 5.0V, nominal power setting (R1, R2, R4, and R5 not installed) VCC = 5.0V, nominal power setting (R1, R2, R4, and R5 not installed) VCC = 5.0V, nominal power setting (R1, R2, R4, and R5 not installed) MIN 700 TYP MAX 1100 UNITS MHz MAX9987/MAX9988 14.3 Output Power (Main Drivers) POUTLO 17.3 0.8 dBm 19.7 3.7 1.2:1 1.7:1 -152 45 39 48 50 dBm/Hz dB dB dB dB dBm _______________________________________________________________________________________ 3 +14dBm to +20dBm LO Buffers/Splitters with 1dB Variation MAX9987/MAX9988 AC ELECTRICAL CHARACTERISTICS--MAX9988 (Typical Application Circuit, VCC = 4.75V to 5.25V, 50 environment, +6dBm < PIN < +12dBm, 1500MHz < fIN < 2200MHz, and TA = -40C to +85C, unless otherwise noted. Typical specifications are for VCC = 5.0V, PIN = +9dBm, fIN = 1800MHz, and TA = +25C unless otherwise noted.) (Note 1) PARAMETER Operating Frequency SYMBOL f Low power setting, PIN = +6dBm (see Table 1 for resistor values) Output Power (Main Drivers) Nominal power setting, +6dBm < PIN < +12dBm, 4.75V < VCC < 5.25V, -40C < TA < +85C (R1, R2, R4, and R5 not installed) High power setting, PIN = +12dBm (see Table 1 for resistor values) Output Power (PLL Driver) Input VSWR Output VSWR Output-Noise Power Density OUT1 to OUT2 Isolation OUT2 to OUT1 Isolation OUT1 to RFIN Isolation OUT2 to RFIN Isolation POUTPLL VSWRIN VSWROUT PNOISE S23 S32 S12 S13 VCC = 5.0V, 100MHz offset VCC = 5.0V, nominal power setting (R1, R2, R4, and R5 not installed) VCC = 5.0V, nominal power setting (R1, R2, R4, and R5 not installed) VCC = 5.0V, nominal power setting (R1, R2, R4, and R5 not installed) VCC = 5.0V, nominal power setting (R1, R2, R4, and R5 not installed) CONDITIONS MIN 1500 14.2 TYP MAX 2200 UNITS MHz POUTLO 17.3 0.8 dBm 19.5 3.6 1.5:1 1.4:1 -152 33 44 49 47 dBm/Hz dB dB dB dB dBm Note 1: Devices are 100% DC screened and AC production tested for functionality. Data sheet typical specifications are derived from the average of 30 units from a typical lot, and are tested under the conditions specified for the typical specifications. 4 _______________________________________________________________________________________ +14dBm to +20dBm LO Buffers/Splitters with 1dB Variation Typical Operating Characteristics (VCC = 5.0V, nominal bias, fIN = 900MHz, PIN = +7dBm, TA = +25C, unless otherwise noted.) (Shaded regions are outside the guaranteed operating range, and are provided for reference only.) MAX9987/MAX9988 MAX9987 SUPPLY CURRENT vs. OUTPUT POWER OUTMAIN MAX9987 toc01 OUTPUT POWER vs. INPUT POWER OUT1 20 19 18 OUTPUT POWER (dBm) 17 16 15 14 13 12 11 10 TA = +85C TA = +25C TA = -40C OUTPUT POWER (dBm) MAX9987 toc02 OUTPUT POWER vs. INPUT POWER OUT2 20 19 18 17 16 15 14 13 12 11 10 TA = +85C TA = +25C TA = -40C MAX9987 toc03 180 175 SUPPLY CURRENT (mA) 170 165 160 155 TA = -40C 150 145 140 -15 -10 -5 0 5 10 15 TA = +25C AND +85C 20 OUTPUT POWER (dBm) -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 INPUT POWER (dBm) -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 INPUT POWER (dBm) OUTPUT POWER vs. INPUT POWER, OUTPLL MAX9987 toc04 OUTPUT POWER vs. FREQUENCY, OUT1 MAX9987 toc05 OUTPUT POWER vs. FREQUENCY, OUT2 MAX9987 toc06 5 4 3 OUTPUT POWER (dBm) 2 1 0 -1 -2 -3 -4 -5 -6 -4 -2 0 2 4 6 8 TA = +85C TA = +25C TA = -40C 20 19 OUTPUT POWER (dBm) TA = +25C 18 17 16 15 14 TA = +85C 20 19 OUTPUT POWER (dBm) 18 17 TA = +85C 16 15 14 TA = -40C TA = +25C TA = -40C 10 500 600 700 800 900 1000 1100 1200 500 600 700 800 900 1000 1100 1200 INPUT POWER (dBm) OPERATING FREQUENCY (MHz) OPERATING FREQUENCY (MHz) OUTPUT POWER vs. FREQUENCY, PLL MAX9987 toc07 OUTPUT POWER AND SUPPLY CURRENT vs. TEMPERATURE 18.0 17.8 17.6 OUTPUT POWER (dBm) 17.4 17.2 17.0 16.8 16.6 16.4 16.2 POUT ICC MAX9987 toc08 OUTPUT POWER vs. SUPPLY VOLTAGE 162.0 OUT1, OUT2 OUTPUT POWER (dBm) 161.8 SUPPLY CURRENT (mA) 161.6 161.4 161.2 161.0 160.8 160.6 160.4 160.2 160.0 18.0 17.5 17.0 16.5 16.0 15.5 15.0 14.5 14.0 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5 SUPPLY VOLTAGE (V) OUTPLL OUT2 OUT1 MAX9987 toc09 6 5 OUTPUT POWER (dBm) 4 3 2 1 0 500 600 700 800 TA = -40C TA = +25C T = +85C A 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 PLL OUTPUT POWER (dBm) 900 1000 1100 1200 16.0 -40 -20 0 20 40 60 80 AMBIENT TEMPERATURE (C) OPERATING FREQUENCY (MHz) _______________________________________________________________________________________ 5 +14dBm to +20dBm LO Buffers/Splitters with 1dB Variation MAX9987/MAX9988 Typical Operating Characteristics (continued) (VCC = 5.0V, nominal bias, fIN = 900MHz, PIN = +7dBm, TA = +25C, unless otherwise noted.) (Shaded regions are outside the guaranteed operating range, and are provided for reference only.) MAX9987 SUPPLY CURRENT vs. SUPPLY VOLTAGE MAX9987 toc10 SMALL-SIGNAL GAIN vs. FREQUENCY VCC = 5.0V TA = +25C PIN = -15dBm NOMINAL BIAS MAX9987 toc11 INPUT RETURN LOSS vs. FREQUENCY -5 -10 RETURN LOSS (dB) -15 -20 -25 -30 VCC = 5.0V TA = +25C PIN = +7dBm MAX9987 toc12 170 165 SUPPLY CURRENT (mA) 160 PLL BIASED 155 150 145 140 PLL NOT BIASED 19 18 17 GAIN (dB) 16 15 14 13 0 OUT2 OUT1 -35 -40 0.5 0.6 0.7 0.8 0.9 1.0 1.1 0.5 0.6 0.7 0.8 0.9 1.0 1.1 FREQUENCY (GHz) FREQUENCY (GHz) 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5 SUPPLY VOLTAGE (V) OUTPUT RETURN LOSS vs. FREQUENCY MAX9987 toc13 IN ISOLATION vs. FREQUENCY -25 -30 ISOLATION (dB) -35 -40 -45 -50 -55 -60 -65 -70 OUT1 TO IN OUT2 TO IN PLL TO IN VCC = 5.0V TA = +25C PIN = +7dBm MAX9987 toc14 OUT1 AND OUT2 ISOLATION vs. FREQUENCY -25 -30 ISOLATION (dB) -35 -40 -45 -50 -55 -60 -65 -70 OUT2 TO OUT1 OUT1 TO OUT2 VCC = 5.0V TA = +25C PIN = +7dBm MAX9987 toc15 0 -2 -4 RETURN LOSS (dB) -6 -8 -10 -12 -14 -16 -18 -20 0.5 0.6 0.7 0.8 0.9 1.0 PLL OUT2 VCC = 5.0V TA = +25C PIN = +7dBm OUT1 -20 -20 1.1 0.5 0.6 0.7 0.8 0.9 1.0 1.1 0.5 0.6 0.7 0.8 0.9 1.0 1.1 FREQUENCY (GHz) FREQUENCY (GHz) FREQUENCY (GHz) PLL ISOLATION vs. FREQUENCY MAX9987 toc16 OUTPUT NOISE POWER vs. INPUT POWER 100MHz OFFSET NOISE POWER (dBm/Hz) -145 MAX9987 toc17 -20 -25 -30 ISOLATION (dB) -35 -40 -45 -50 -55 -60 -65 -70 0.5 0.6 0.7 0.8 0.9 1.0 OUT1 TO PLL OUT2 TO PLL PLL TO OUT_ VCC = 5.0V TA = +25C PIN = +7dBm -140 -150 -155 -160 1.1 4 5 6 7 8 9 10 FREQUENCY (GHz) INPUT POWER (dBm) 6 _______________________________________________________________________________________ +14dBm to +20dBm LO Buffers/Splitters with 1dB Variation Typical Operating Characteristics (continued) (VCC = 5.0V, nominal bias, fIN = 1800MHz, PIN = +7dBm, TA = +25C, unless otherwise noted.) (Shaded regions are outside the guaranteed operating range, and are provided for reference only.) MAX9987/MAX9988 MAX9988 SUPPLY CURRENT vs. OUTPUT POWER MAX9988 toc01 OUTPUT POWER vs. INPUT POWER, OUT1 MAX9988 toc02 OUTPUT POWER vs. INPUT POWER, OUT2 19 18 OUTPUT POWER (dBm) 17 16 15 14 13 12 11 TA = +85C TA = -40C TA = +25C MAX9988 toc03 180 175 SUPPLY CURRENT (mA) 170 165 160 TA = +25C 155 150 145 140 -15 -10 -5 0 5 10 15 TA = -40C TA = +85C 20 19 18 OUTPUT POWER (dBm) 17 16 15 14 13 12 11 10 TA = +85C TA = +25C TA = -40C 20 20 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 INPUT POWER (dBm) 10 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 INPUT POWER (dBm) OUTPUT POWER (dBm) OUTPUT POWER vs. INPUT POWER, OUTPLL MAX9988 toc04 OUTPUT POWER vs. FREQUENCY, OUT1 MAX9988 toc05 OUTPUT POWER vs. FREQUENCY, OUT2 19 18 OUTPUT POWER (dBm) 17 16 15 14 13 12 11 10 TA = +25C TA = +85C TA = -40C MAX9988 toc06 MAX9988 toc09 5 4 3 OUTPUT POWER (dBm) 2 1 0 -1 -2 -3 -4 -5 -6 -4 -2 0 2 4 6 8 TA = -40C TA = +25C AND +85C 20 19 18 OUTPUT POWER (dBm) 17 16 15 14 13 12 11 10 TA = +25C TA = -40C 20 TA = +85C 10 1500 1600 1700 1800 1900 2000 2100 2200 OPERATING FREQUENCY (MHz) 1500 1600 1700 1800 1900 2000 2100 2200 OPERATING FREQUENCY (MHz) INPUT POWER (dBm) OUTPUT POWER vs. FREQUENCY, OUTPLL MAX9988 toc07 OUTPUT POWER AND SUPPLY CURRENT vs. TEMPERATURE 18.0 17.8 17.6 17.4 17.2 17.0 16.8 16.6 16.4 16.2 16.0 15.8 15.6 15.4 15.2 15.0 -40 -20 0 MAX9988 toc08 OUTPUT POWER vs. SUPPLY VOLTAGE 190 188 186 184 182 180 178 176 174 172 170 168 166 164 162 160 18.0 OUT1, OUT2 OUTPUT POWER (dBm) 17.5 17.0 16.5 16.0 15.5 15.0 14.5 14.0 OUTPLL 3.5 3.0 2.5 2.0 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5 SUPPLY VOLTAGE (V) OUT2 OUT1 6.0 5.5 5.0 4.5 4.0 PLL OUTPUT POWER (dBm) 6 5 OUTPUT POWER (dBm) 4 3 TA = -40C 2 1 0 TA = +85C TA = +25C OUTPUT POWER (dBm) POUT ICC 1500 1600 1700 1800 1900 2000 2100 2200 OPERATING FREQUENCY (MHz) 20 40 60 80 AMBIENT TEMPERATURE (C) _______________________________________________________________________________________ SUPPLY CURRENT (mA) 7 +14dBm to +20dBm LO Buffers/Splitters with 1dB Variation MAX9987/MAX9988 Typical Operating Characteristics (continued) (VCC = 5.0V, nominal bias, fIN = 1800MHz, PIN = +7dBm, TA = +25C, unless otherwise noted.) (Shaded regions are outside the guaranteed operating range, and are provided for reference only.) MAX9988 SUPPLY CURRENT vs. SUPPLY VOLTAGE MAX9988 toc10 SMALL-SIGNAL GAIN vs. FREQUENCY 17 16 OUT2 VCC = 5.0V TA = +25C PIN = -15dBm NORMAL BIAS MAX9988 toc11 INPUT RETURN LOSS vs. FREQUENCY VCC = 5.0V TA = +25C PIN = +7dBm MAX09988 toc12 180 175 SUPPLY CURRENT (mA) 170 PLL BIASED 165 160 155 150 PLL NOT BIASED 18 -6 -8 RETURN LOSS (dB) -10 -12 -14 -16 GAIN (dB) 15 14 13 12 11 10 OUT1 -18 -20 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 FREQUENCY (GHz) FREQUENCY (GHz) 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5 SUPPLY VOLTAGE (V) OUTPUT RETURN LOSS vs. FREQUENCY MAX9988 toc13 OUT TO IN ISOLATION vs. FREQUENCY MAX9988 toc14 OUT TO OUT ISOLATION vs. FREQUENCY -20 -25 ISOLATION (dB) -30 -35 -40 -45 -50 -55 OUT2 TO OUT1 OUT1 TO OUT2 VCC = 5.0V TA = +25C PIN = +7dBm MAX9988 toc15 0 -5 -10 RETURN LOSS (dB) -15 -20 -25 -30 -35 -40 1.5 1.6 1.7 1.8 1.9 2.0 2.1 OUT1 OUTPLL VCC = 5.0V TA = +25C PIN = +7dBm OUT2 -15 -20 -25 ISOLATION (dB) -30 -35 -40 -45 -50 -55 -60 -65 OUT1 TO IN 1.5 1.6 1.7 1.8 1.9 2.0 2.1 OUT2 TO IN PLL TO IN VCC = 5.0V TA = +25C PIN = +7dBm -15 -60 -65 2.2 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.2 FREQUENCY (GHz) FREQUENCY (GHz) FREQUENCY (GHz) PLL ISOLATION vs. FREQUENCY MAX9988 toc16 OUTPUT NOISE vs. INPUT POWER 100MHz OFFSET MAX9988 toc17 0 -5 -10 ISOLATION (dB) -15 -20 -25 -30 -35 -40 -45 -50 1.5 1.6 1.7 1.8 1.9 2.0 2.1 OUT1 TO PLL OUT2 TO PLL PLL TO OUT_ VCC = 5.0V TA = +25C PIN = +7dBm -140 OUTPUT NOISE (dBm/Hz) 2.2 -145 -150 -155 -160 4 5 6 7 8 9 10 FREQUENCY (GHz) INPUT POWER (dBm) 8 _______________________________________________________________________________________ +14dBm to +20dBm LO Buffers/Splitters with 1dB Variation Pin Description PIN 1, 4, 8, 9, 13, 17, 18, EP 2 3 5 NAME GND IN VCCREF REF Ground Input. Internally matched 50 RF input. AC couple to this pin. Supply. Supply connection for on-chip voltage and current references. See Applications Information for information on decoupling. Voltage Reference Output. Output for on-chip 1.5V bandgap voltage reference. See Applications Information section for information on decoupling. Bias Connection for Input Buffer. Set compressed power point for input amplifier with a resistor to REF or GND. For +17dBm output power, no external biasing resistors are required. See Applications Information section for information. Bias Connection for Output Amplifiers. Set compressed power point for OUT1 and OUT2 with a resistor to REF or ground. For +17dBm output power, no external biasing resistors are required. See Applications Information section for information. Output 2. Internally matched 50 RF output. AC couple to this pin. Supply. Supply connection for OUT2. Supply. Supply connection for OUT1. Output 1. Internally matched 50 RF output. AC couple to this pin. Supply. Supply connection for input amplifier. Output PLL. Output for driving optional external PLL. FUNCTION MAX9987/MAX9988 6 BIASIN 7 10 11, 12 14, 15 16 19 20 BIASOUT OUT2 VCC3 VCC2 OUT1 VCC1 OUTPLL Detailed Description The MAX9987/MAX9988 LO amplifiers/splitters each consist of a single input amplifier, a two-way passive power splitter, two separate output amplifiers, as well as a third buffer amplifier to drive the LO's PLL. The bias currents for the amplifiers are adjustable through off-chip resistors. This allows the output level to be precision set anywhere from +14dBm to +20dBm. The PLL output is preset to +3dBm (about 900mVP-P into 50). Power levels are typically 1dB over the full supply, input power, frequency, and temperature range. Precision power control is achieved by internal control circuitry. Maintaining tight power control keeps the system engineer from over specifying the LO drive in order to guarantee a linearity specification in the base-station mixer. More than 40dB isolation between the LO outputs and the input prevents VCO pulling, and the 30dB outputto-output isolation reduces branch-to-branch coupling. The MAX9987 is specified from 700MHz to 1100MHz, and the MAX9988 is specified from 1500MHz to 2200MHz. Both are offered in compact 5mm 5mm 20pin QFN packages with exposed paddle. Input Amplifier A single low-noise input amplifier before the passive splitter provides gain and isolation. The compressed output power for this stage is controlled by the bias setting resistors R1 or R4 (see Typical Application Circuit). These resistors are not required for the nominal +17dBm output; see Table 1 for bias resistor values to obtain +14dBm to +20dBm output power. The input is internally matched to 50, and typical VSWR is no more than 2:1 over all operating conditions. Since the input is internally biased, provide a DC block at the input pin. PLL Amplifier and Output A small amount of power is tapped off from the input amplifier's output, and fed to a high-isolation buffer to drive the PLL output at +3dBm. If the PLL output is not required, it can be disabled by removing R3; disabling the PLL output saves 12mA supply current. Passive Two-Way Splitter The input amplifier drives an integrated power splitter. All impedance matching between stages is on-chip, so no external tuning components are required. _______________________________________________________________________________________ 9 +14dBm to +20dBm LO Buffers/Splitters with 1dB Variation MAX9987/MAX9988 Table 1. External Resistor Values for +14dBm to +20dBm Output Power NOMINAL OUTPUT POWER (dBm) +20 +19 +18 +17 +16 +15 +14 R1 () 1.35k 2.2k 5.0k Open Open Open Open R2 () 2.0k 3.0k 6.0k Open Open Open Open R4 () Open Open Open Open 1.8k 0.9k 0.6k R5 () Open Open Open Open 3.0k 1.1k 0.6k MAX9987 INPUT DRIVE (dBm) 10 3 9 3 8 3 7 3 6 3 5 3 4 3 MAX9988 INPUT DRIVE (dBm) 12 3 11 3 10 3 9 3 8 3 7 3 6 3 Table 2. Component Values for Typical Application Circuit COMPONENT VALUE DESIGNATION C1, C3, C6 C2, C4, C5, C7, C8, C9, C12, C13, C14 C10, C11 R1, R2, R4, R5 R3 MAX9987 (LOWBAND) 100pF 47pF 5pF See Table 1. 100 MAX9988 (HIGHBAND) 100nF 22pF 10pF See Table 1. 100 Applications Information Input and Output Matching All input and output matching is accomplished on-chip; no external matching circuitry is required. Use a DC block of about 47pF (lowband) or 22pF (highband) at the input and the outputs. Because these parts are internally broadband matched, adjusting external component values can optimize performance for a particular band. Input Drive Level In the case of the MAX9987, the typical required input drive level is +7dBm for +17dBm output, or +10dBm for +20dBm output. The MAX9988 uses slightly higher input levels (see Table 1). The typical VCO cannot provide sufficient drive by itself; the typical application follows the VCO with attenuation (about +3dB), and then with a low-noise gain block. This allows the VCO to drive the MAX9987/MAX9988 input at the required level without being load-pulled. Driver Amplifiers and Outputs Each of the output amplifiers are similar to the input amplifier, except they are biased higher to provide more output power. For example, with an input power of +10dBm, the MAX9987 can deliver +20dBm at both outputs. The bias is adjustable; see Table 1 for details. Both RF outputs are internally matched to 50, with a typical VSWR limit of 2:1. Provide DC blocking capacitors at the outputs. Output Drive Level The output drive of the MAX9987/MAX9988 is nominally +17dBm 1dB. This is the typical application, with no external bias-setting resistors at INBIAS and OUTBIAS. Output power can be set from +14dBm to +20dBm by using the bias-setting resistor values listed in Table 1. Chip Information TRANSISTOR COUNT: 89 PROCESS: BiCMOS 10 ______________________________________________________________________________________ +14dBm to +20dBm LO Buffers/Splitters with 1dB Variation Typical Application Circuit/Pin Configuration 5.0V 5.0V MAX9987/MAX9988 C1 C2 C3 R3 100 C4 MAX9987 MAX9988 C13 TO OUTPUT 1 OUTPLL VCC1 GND OUT TO PLL (+3dBm) C14 GND OUT1 20 GND 19 18 17 16 VCC2 C11 C12 5.0V 1 15 INPUT FROM LO C5 5.0V C6 C7 IN VCCREF 2 14 VCC2 GND 3 13 GND 4 BIAS 5 12 VCC3 5.0V REF 11 VCC3 C10 C9 6 7 8 9 10 GND GND BIASIN BIASOUT OUT2 R4* R5* C8 TO OUTPUT 2 R1* R2* * FOR THESE VALUES, SEE TABLE 1. FOR CAPACITOR VALUES, SEE TABLE 2. ______________________________________________________________________________________ 11 +14dBm to +20dBm LO Buffers/Splitters with 1dB Variation MAX9987/MAX9988 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.) 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. 12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. |
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