19-1466; Rev 0; 6/99 ANUAL N KIT M EET IO T A U EVAL TA SH WS DA FOLLO 500MHz to 2500MHz VCO Buffer Amplifiers The MAX2472/MAX2473 are flexible, wideband, highreverse-isolation buffer amplifiers. The MAX2472 has dual open-collector outputs capable of delivering -5dBm into 50 while maintaining harmonic suppression below -25dBc. The MAX2473 has a single open-collector output with a bias control pin to vary output power from -10dBm to -2dBm while maintaining harmonic suppression below -25dBc. The MAX2472/MAX2473's combination of high reverse isolation and low supply current makes them ideal for applications requiring high performance with low power. They feature high input impedance and open-collector outputs for maximum flexibility, enabling them to be used with a variety of oscillator topologies. Both the MAX2472 and MAX2473 operate from a single +2.7V to +5.5V supply. With VCC = +3.0V and -25dBm input power, the MAX2472 consumes 5.2mA, while the MAX2473 consumes only 2.7mA. Both devices are available in a tiny 6-pin SOT23 package requiring minimal board space. Features +2.7V to +5.5V Supply Range 500MHz to 2500MHz Input Frequency Range High Reverse Isolation: 49dB at 900MHz Dual Open-Collector Outputs (MAX2472) Adjustable -10dBm to -2dBm Output Power Control (MAX2473) High Input Impedance: >250 at 900MHz Ultra-Small SOT23-6 Package Ordering Information PART TEMP. RANGE PINPACKAGE SOT TOP MARK MAX2472EUT-T -40C to +85C 6 SOT23-6 AAAZ MAX2473EUT-T -40C to +85C 6 SOT23-6 AABA Applications Functional Diagrams Cellular and PCS Mobile Phones Private Mobile Radios VCC ISM-Band Applications BIAS IF/RF Oscillators OUT2 General-Purpose Buffers/Amplifiers MAX2472 IN Typical Operating Circuits appear at end of data sheet. OUT1 GND Pin Configuration GND VCC TOP VIEW BIAS BIAS OUT1 (OUT) 1 6 VCC MAX2473 GND 2 MAX2472 MAX2473 OUT2 (BIAS) 3 5 GND OUT IN 4 IN GND GND SOT23-6 ( ) ARE FOR MAX2473. ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. MAX2472/MAX2473 General Description MAX2472/MAX2473 500MHz to 2500MHz VCO Buffer Amplifiers ABSOLUTE MAXIMUM RATINGS VCC to GND ..............................................................-0.3V to +7V OUT1, OUT2, BIAS to GND........................-0.3V to (VCC + 0.3V) Maximum BIAS Pin Current................................................150A Maximum Input Power....................................................+10dBm Continuous Power Dissipation SOT23-6 (derate 8.7mW/C above +70C)...................696mW Operating Temperature Range ...........................-40C to +85C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10sec) .............................+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 (VCC = +2.7V to +5.5V, PIN = -25dBm, IN driven from a 50 source, OUT_ LC-matched to 50, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3V, TA = +25C.) (Note 1) PARAMETER Input Voltage Range Supply Current SYMBOL CONDITIONS VCC ICC MIN TYP 2.7 MAX2472 5.2 MAX2473, RBIAS = 23k 2.7 MAX2473, RBIAS = 11k 4.8 No drive MAX2472 5.1 MAX2473, RBIAS = 23k 2.5 MAX2473, RBIAS = 11k 4.3 MAX UNITS 5.5 V 8.0 mA AC ELECTRICAL CHARACTERISTICS--MAX2472 (Typical Operating Circuits, VCC = +3V, PIN = -25dBm, IN driven from a 50 source, OUT1 and OUT2 LC matched to 50, TA = +25C, unless otherwise noted.) PARAMETER SYMBOL Input Frequency Range (Note 2) fIN CONDITIONS MIN 500 fIN = 600MHz Transducer Gain (IN to OUT2) S212 Output 1dB Compression Point Reverse Isolation (IN to OUT2) 2 S212 POUT1dB S122 MAX UNITS 2500 MHz 14.0 fIN = 900MHz, TA = +25C 7.8 fIN = 900MHz, TA = TMIN to TMAX (Note 3) 6.6 fIN = 1900MHz Transducer Gain (IN to OUT1) TYP 10.2 12.2 14.6 dB 7.5 fIN = 2400MHz 6.0 fIN = 600MHz 13.0 fIN = 900MHz 9.2 fIN = 1900MHz 6.8 fIN = 2400MHz 5.3 fIN = 900MHz -3.2 fIN = 600MHz 43 fIN = 900MHz 40 fIN = 1900MHz 30 fIN = 2400MHz 26 _______________________________________________________________________________________ dB dBm dB 500MHz to 2500MHz VCO Buffer Amplifiers (Typical Operating Circuits, VCC = +3V, PIN = -25dBm, IN driven from a 50 source, OUT1 and OUT2 LC matched to 50, TA = +25C, unless otherwise noted.) PARAMETER Reverse Isolation (IN to OUT1) SYMBOL S122 Noise Figure NF CONDITIONS MIN TYP fIN = 600MHz 54 fIN = 900MHz 49 fIN = 1900MHz 34 fIN = 2400MHz 30 fIN = 900MHz 9.5 fIN = 1900MHz 10.2 MAX UNITS dB dB Isolation (OUT1 to OUT2) fIN = 900MHz 24 dB Harmonic Suppression POUT = -5dBm, fIN = 900MHz -25 dBc AC ELECTRICAL CHARACTERISTICS--MAX2473 (Typical Operating Circuits, VCC = +3V, PIN = -25dBm, RBIAS = 15k, IN driven from a 50 source, OUT LC matched to 50, TA = +25C, unless otherwise noted.) PARAMETER SYMBOL Input Frequency Range (Note 2) fIN CONDITIONS MIN 500 fIN = 600MHz S212 Transducer Gain fIN = 900MHz, TA = +25C 6.8 fIN = 900MHz, TA = TMIN to TMAX (Note 3) 6.4 S122 Reverse Isolation Noise Figure NF Harmonic Suppression fIN = 900MHz UNITS 2500 MHz 11.8 16.8 19.0 dB 7.6 fIN = 2400MHz POUT1dB MAX 14.8 fIN = 1900MHz Output 1dB Compression Point TYP 7.2 RBIAS = 23k -6.0 RBIAS = 11k -0.9 fIN = 600MHz 50 fIN = 900MHz 48 fIN = 1900MHz 35 fIN = 2400MHz 29 fIN = 900MHz 9.2 fIN = 1900MHz 9.9 POUT = -5dBm, fIN = 900MHz -25 dBm dB dB dBc Note 1: Limits are 100% production tested at TA = +25C. Limits over the entire operating temperature range are guaranteed by design and characterization but are not production tested. Note 2: This is the recommended operating frequency range. The parts have been characterized over the specified frequency range and production tested at 900MHz. Operation outside of this range is possible but not guaranteed. Note 3: Guaranteed by design and characterization. _______________________________________________________________________________________ 3 MAX2472/MAX2473 AC ELECTRICAL CHARACTERISTICS--MAX2472 (continued) Typical Operating Characteristics (MAX2472/MAX2473 EV kit, VCC = +3V, TA = +25C, unless otherwise noted.) MAX2472 MAX2472 toc01 PIN = -20dBm fIN = 900MHz 12 10 S21 2 (dB) 6.0 VCC = 5V ICC (mA) PIN = -20dBm fIN = 600MHz 14 MAX2472 toc02 S21 2 vs. TEMPERATURE SUPPLY CURRENT vs. TEMPERATURE 7.0 VCC = 3V 8 fIN = 900MHz fIN = 1900MHz 6 5.0 4 fIN = 2400MHz 2 -20 0 20 40 60 0 -50 80 -30 -10 10 30 50 TEMPERATURE (C) TEMPERATURE (C) S21 2 vs. OUTPUT POWER S11 90 MAX2472 toc03 14 70 fIN = 600MHz 12 MAX2472 toc06 4.0 -40 10 S21 2 (dB) fIN = 900MHz fIN = 1900MHz 8 6 A fIN = 2400MHz D 4 FOR OUT1 WITH OUT2 REACTIVELY MATCHED AND TERMINATED 0 -20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0 FOR OUT2 WITH OUT1 BIASED AND TERMINATED POUT (dBm) S21 B A: fIN = 600MHz B: fIN = 900MHz C: fIN = 1900MHz D: fIN = 2400MHz S22 S12 MAX2472 toc08 MAX2472 toc09 2 C MAX2472 toc07 MAX2472/MAX2473 500MHz to 2500MHz VCO Buffer Amplifiers D BA C D A C B D B C A (3 UNITS FULL SCALE) FOR OUT2 WITH OUT1 BIASED AND TERMINATED 4 A: fIN = 600MHz B: fIN = 900MHz C: fIN = 1900MHz D: fIN = 2400MHz (0.1 UNITS FULL SCALE) FOR OUT2 WITH OUT1 BIASED AND TERMINATED A: fIN = 600MHz B: fIN = 900MHz C: fIN = 1900MHz D: fIN = 2400MHz FOR OUT2 WITH OUT1 BIASED AND TERMINATED _______________________________________________________________________________________ A: fIN = 600MHz B: fIN = 900MHz C: fIN = 1900MHz D: fIN = 2400MHz 500MHz to 2500MHz VCO Buffer Amplifiers MAX2472 SCATTERING PARAMETERS (IN to OUT 2) _______________________________________________________________________________________ 5 MAX2472/MAX2473 Typical Operating Characteristics (continued) (MAX2472/MAX2473 EV kit, VCC = +3V, TA = +25C, unless otherwise noted.) Typical Operating Characteristics (continued) (MAX2472/MAX2473 EV kit, VCC = +3V, TA = +25C, unless otherwise noted.) MAX2473 14 7 VCC = 5V 5 14 fIN = 900MHz 10 8 fIN = 1900MHz VCC = 3V 2 fIN = 2400MHz 35 30 25 20 15 0 -50 10 -25 S21 2 vs. OUTPUT POWER fIN = 1900MHz 16 18 12 S21 2 (dB) 14 RBIAS = 11k 8 -15 0 -25 100 18 10 RBIAS = 15k -10 POUT (dBm) RBIAS = 22k 8 2 -4 RBIAS = 15k 10 0 -20 -8 RBIAS = 11k 12 4 -12 fIN = 600MHz 6 RBIAS = 22k -16 0 14 2 0 -5 16 RBIAS = 22k -5 -10 S21 2 vs. OUTPUT POWER RBIAS = 11k 8 -15 20 4 POUT (dBm) -20 POUT (dBm) fIN = 900MHz 6 RBIAS = 15k 4 0 -20 75 16 12 2 50 S21 2 vs. OUTPUT POWER 14 6 25 20 MAX2472 toc13b 20 10 RBIAS = 22k TEMPERATURE (C) RBIAS (k) 18 0 S21 2 (dB) 40 RBIAS = 15k 2 MAX2472 toc13c 45 RBIAS = 11k 4 2 50 10 6 4 1 12 8 6 3 fIN = 2400MHz 16 S21 2 (dB) 6 4 6 18 12 S21 2 (dB) ICC (mA) fIN = 600MHz MAX2472 toc13a 8 PIN = -20dBm RBIAS = 15k 16 20 MAX2472 toc12 18 MAX2472 toc11 9 0 S21 2 vs. OUTPUT POWER S21 2 vs. TEMPERATURE 10 MAX2472 toc13d SUPPLY CURRENT vs. RBIAS S21 2 (dB) MAX2472/MAX2473 500MHz to 2500MHz VCO Buffer Amplifiers 0 0 -20 -15 -10 -5 POUT (dBm) _______________________________________________________________________________________ 0 5 500MHz to 2500MHz VCO Buffer Amplifiers MAX2473 S11 MAX2472 toc15 -30 fIN = 900MHz -35 REVERSE ISOLATION (dB) MAX2472 toc16 REVERSE ISOLATION vs. RBIAS -40 -45 D -50 A B C -55 -60 0 5 10 15 20 25 30 35 RBIAS = 15k 40 RBIAS (k) S21 A: fIN = 600MHz B: fIN = 900MHz C: fIN = 1900MHz D: fIN = 2400MHz S22 MAX2472 toc19 MAX2472 toc17 MAX2472 toc18 S12 D A C B A D B C (3 UNITS FULL SCALE) RBIAS = 15k D B A A: fIN = 600MHz B: fIN = 900MHz C: fIN = 1900MHz D: fIN = 2400MHz C (0.1 UNITS FULL SCALE) RBIAS = 15k A: fIN = 600MHz B: fIN = 900MHz C: fIN = 1900MHz D: fIN = 2400MHz RBIAS = 15k A: fIN = 600MHz B: fIN = 900MHz C: fIN = 1900MHz D: fIN = 2400MHz _______________________________________________________________________________________ 7 MAX2472/MAX2473 Typical Operating Characteristics (continued) (MAX2472/MAX2473 EV kit, VCC = +3V, TA = +25C, unless otherwise noted.) MAX2472/MAX2473 500MHz to 2500MHz VCO Buffer Amplifiers Typical Operating Characteristics (continued) (MAX2472/MAX2473 EV kit, VCC = +3V, TA = +25C, unless otherwise noted.) MAX2473 SCATTERING PARAMETERS (IN to OUT) 8 _______________________________________________________________________________________ 500MHz to 2500MHz VCO Buffer Amplifiers PIN NAME FUNCTION MAX2472 MAX2473 1 -- OUT1 Open-Collector Buffer Output 1. Connect to VCC via a resistor or inductor/choke. AC-coupling to the output is required. -- 1 OUT Open-Collector Buffer Output. Connect to VCC via a resistor or inductor/choke. AC-coupling to the output is required. 2, 5 2, 5 GND RF Ground. Connect to the ground plane as close to the IC as possible to minimize trace inductance. 3 -- OUT2 Open-Collector Buffer Output 2. Connect to VCC via a resistor or inductor/choke. AC-coupling to the output is required. -- 3 BIAS Bias Resistor Connection. Connect a resistor from BIAS to GND to set the output stage bias current and gain. To choose RBIAS, refer to the Typical Operating Characteristics for the MAX2473. 4 4 IN High-Impedance Input to the Buffer Amplifier 6 6 VCC Supply Voltage Input: +2.7V < VCC < +5.5V Table 1. Output Matching Components OPERATING FREQUENCY (MHz) LMATCH CMATCH 600 22nH Coilcraft 0603HS-22NTJBC 1.5pF Murata GRM39COG1R5B50V 900 12nH Coilcraft 0603HS-12NTJBC 1pF Murata GRM39COG1R0B50V 1900 2.2nH Murata LQG11AZN2500 1pF Murata GRM39COG1R0B50V 2400 1.2nH Murata LQG11AINZS00 1pF Murata GRM39COG1R0B50V Detailed Description The MAX2472/MAX2473 are ideal replacements for discrete solutions where a VCO output must drive more than one input, especially where high reverse isolation and low supply currents are mandatory. The MAX2472 features a two-stage wideband architecture with a highinput-impedance common-emitter amplifier followed by two separate open-collector output stages. The MAX2473 features a two-stage wideband architecture with a high-input-impedance common-emitter amplifier followed by one open-collector output stage, with the added feature of output power control. Using values for RBIAS from 11k to 23k allows the output power of the MAX2473 to range from -2dBm to -10dBm. _______________________________________________________________________________________ 9 MAX2472/MAX2473 Pin Description MAX2472/MAX2473 500MHz to 2500MHz VCO Buffer Amplifiers VCC (PIN 6) VCC (PIN 6) INTERNAL 1.2V REFERENCE 250 1.3pF 1k 1k BIAS (PIN 3) IN (PIN 4) GND (PIN 2) 33 Figure 3. BIAS Structure (MAX2473 only) GND (PIN 5) Figure 1. Input Structure VCC (PIN 6) 2k OUT the MAX2472/MAX2473 from the S parameter tables in the Typical Operating Characteristics. Terminate the buffer input with a shunt resistor "RTERM" such that RTERM || RE[S11] = 50, and use a series blocking capacitor between the shunt resistor and the device input. This provides a very stable 50 termination and increases reverse isolation. For those applications needing both high gain and good input match, reactively match the buffer inputs to 50 with simple twoelement matching circuits. Figure 1 shows an equivalent input circuit of the MAX2472/MAX2473 IN pin. Output Considerations 10 GND (PIN 2) Figure 2. Output Structure Applications Information Input Considerations The MAX2472/MAX2473 offer high-impedance inputs ideal for low-distortion buffering of a VCO. For applications with discrete transistor-based oscillator designs, simply AC-couple the oscillator directly to the input; the buffer's high input impedance results in minimal loading on the oscillator. For use with 50 VCO modules, determine the approximate input impedance (S11) of 10 The MAX2472/MAX2473 outputs are configured as open-collector output stages, allowing maximum flexibility. To achieve maximum gain and output drive, reactively match these outputs with a shunt inductor/choke to VCC followed by a series capacitor (DC block). For applications not requiring high gain and output drive (PLL prescaler), use a simple resistor to VCC followed by a DC blocking capacitor. Figure 2 shows an equivalent circuit of the MAX2472/MAX2473 OUT pin(s). Figure 3 shows an equivalent circuit of the MAX2473 BIAS pin. Output Matching Circuit Table 1 lists recommended values for lumped-element output matching circuits at certain frequencies. For frequencies other than those specified, use the parameters given in the Typical Operating Characteristics. Layout and Power-Supply Bypassing A properly designed PC board is essential to any RF/microwave circuit. Be sure to use controlled impedance lines on all high-frequency inputs and outputs. Bypass the power supply with decoupling capacitors ______________________________________________________________________________________ 500MHz to 2500MHz VCO Buffer Amplifiers uses a topside RF ground, connect both GND pins directly to it. For a board where the ground plane is not on the component side, the best technique is to connect the GND pins to the board with plated throughholes (vias) to the ground plane, located as close to the package as possible. Typical Operating Circuits VCC VCC 0.01F 30pF 1.0F 0.01F VCC LMATCH BIAS TO MIXER CMATCH OUT2 MAX2472 VCO IN OUT1 100pF CMATCH TO MIXER OR PLL GND GND LMATCH 0.01F 30pF VCC VCC 1.0F 0.01F RBIAS VCC BIAS BIAS MAX2473 VCO IN TO MIXER CMATCH 100pF GND LMATCH GND 30pF 0.01F VCC ______________________________________________________________________________________ 11 MAX2472/MAX2473 as close to the VCC pin as possible. For long VCC lines (inductive), it may be necessary to add additional decoupling capacitors located farther away from the device package. Proper connection of the GND pins is essential to achieving maximum reverse isolation. If the PC board 500MHz to 2500MHz VCO Buffer Amplifiers 6LSOT.EPS MAX2472/MAX2473 Package Information Chip Information TRANSISTOR COUNT: 109 12 ______________________________________________________________________________________