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19-5165; Rev 0; 3/10 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator MAX19790 General Description The MAX19790 dual, general-purpose analog voltage variable attenuator (VVA) is designed to interface with 50I systems operating in the 250MHz to 4000MHz frequency range. Each attenuator includes a patented control circuit that provides 22dB of attenuation range with a linear control slope of 10dB/V. Both attenuators share a common analog control and can be cascaded together to yield 44dB of total dynamic range, with a combined linear control slope of 20dB/V. The IC is a monolithic device designed on one of Maxim's proprietary SiGe BiCMOS processes. The device operates from a single +5.0V supply and is available in a compact, 36-pin thin QFN package (6mm x 6mm x 0.8mm) with an exposed pad. Electrical performance is guaranteed over the extended -40 to +85C temperature range. Features S 250MHz to 4000MHz RF Frequency Range S Integrates Two Analog Attenuators in One Monolithic Device S Flexible Attenuation-Control Ranges 22dB (per Attenuator) 44dB (Both Attenuators Cascaded) S 2.4dB 1500MHz Insertion Loss (per Attenuator) S Linear dB/V Analog Control Response Curve Simplifies Automatic Leveling Control and Gain-Trim Algorithms S Excellent Attenuation Flatness Over Wide Frequency Ranges and Attenuation Settings S Low 7.3mA Supply Current S Single +5.0V Supply Voltage Applications Broadband System Applications, Including Wireless Infrastructure Digital and SpreadSpectrum Communication Systems WCDMA/LTE, TD-SCDMA/TD-LTE, WiMAXTM, cdma2000(R), GSM/EDGE, and MMDS Base Stations VSAT/Satellite Modems Microwave Terrestrial Links Lineup Gain Trim Temperature Compensation Circuits Automatic Level Control (ALC) Transmitter Gain Control Receiver Gain Control General Test Equipment PART MAX19790ETX+ Ordering Information TEMP RANGE -40NC to +85NC PIN-PACKAGE 36 Thin QFN-EP* MAX19790ETX+T 36 Thin QFN-EP* -40NC to +85NC +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. T = Tape and reel. WiMAX is a trademark of WiMAX Forum. cdma2000 is a registered trademark of Telecommunications Industry Association. _______________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator MAX19790 ABSOLUTE MAXIMUM RATINGS VCC to GND..........................................................-0.3V to +5.5V CTRL to GND (with VCC = +5.0V applied) ............ 0V to +4.75V All Other Pins to GND .................................-0.3V to VCC + 0.3V RF Input ......................................................................... +20dBm Current into CTRL Pin (VCC grounded) .............................40mA Maximum Junction Temperature.....................................+150C Operating Temperature Range .......................... -40C to +85C Storage Temperature Range............................-65C to +150C Continuous Power Dissipation (TC = +85C) (Note 1) .......2.1W JC (Notes 2, 4) ............................................................ +10C/W JA (Notes 3, 4) ............................................................ +35C/W Lead Temperature (soldering, 10s) ................................+300C Soldering Temperature (reflow) ......................................+260C Note 1: TC is the temperature on the exposed pad of the package. TA is the ambient temperature of the device and PCB. Note 2: Based on junction temperature TJ = TC + (JC x VCC x ICC). This formula can be used when the temperature of the exposed pad is known while the device is soldered down to a PCB. See the Applications Information section for details. The junction temperature must not exceed +150C. Note 3: Junction temperature TJ = TA + (JA x VCC x ICC). This formula can be used when the ambient temperature of the PCB is known. The junction temperature must not exceed +150C. Note 4: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial. 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 (VCC = +4.75V to +5.25V, VCTRL = +1.0V to +4.0V, no RF signals applied, all input and output ports terminated with 50I, TC = -40C to +85C, unless otherwise noted. Typical values are at VCC = +5.0V, VCTRL = +1.0V, TC = +25C, unless otherwise noted.) PARAMETER SUPPLY Supply Voltage Supply Current CONTROL INPUT Control Voltage Range Control Input Resistance VCTRL RCTRL (Note 5) 1.0 50 4.0 V kI VCC ICC 4.75 5.0 7.3 5.25 9.5 V mA SYMBOL CONDITIONS MIN TYP MAX UNITS RECOMMENDED AC OPERATING CONDITIONS PARAMETER RF Frequency Range SYMBOL fRF (Note 6) CONDITIONS MIN 250 TYP MAX 4000 UNITS MHz 2 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator AC ELECTRICAL CHARACTERISTICS (MAX19790 Evaluation Kit, line and connector losses included, two attenuators in cascade, VCC = 4.75V to 5.25V, RF ports are driven from 50I sources, input PRF = -10dBm, fRF = 950MHz to 2150MHz, VCTRL = +1.0V, TC = -40C to +85C. Typical values are for TC = +25C, VCC = +5.0V, input PRF = -10dBm, fRF = 1500MHz, VCTRL = +1.0V, unless otherwise noted.) PARAMETER Insertion Loss Loss Variation Over Temperature Input P1dB Input Second-Order Intercept Point Input Third-Order Intercept Point Second Harmonic Third Harmonic IP1dB IIP2 IIP3 2fIN 3fIN One attenuator, VCTRL = +1.0V to +4.0V, TC = +25NC Attenuation-Control Range AR Two attenuators, VCTRL = +1.0V to +4.0V, TC = +25NC 950MHz to 1500MHz 950MHz to 2150MHz 36 33 fRF1 + fRF2 term, fRF1 - fRF2 = 1MHz (Note 7) fRF1 - fRF2 = 1MHz (Note 7) SYMBOL IL TC = +25NC TC = -40NC to +85NC CONDITIONS 950MHz to 1500MHz 950MHz to 2150MHz MIN TYP 4.4 4.4 0.6 23.1 69.6 36.3 72 77 22 44.7 44.7 20.0 30.4 0.13 500 25 21 190 10 -175 82 0.89 dB/V dB/V dB ns dB dB ps ps ps Degrees dB MAX 6.3 7.0 UNITS dB dB dBm dBm dBm dBc dBc MAX19790 Average Attenuation-Control Slope Maximum Attenuation-Control Slope Attenuation Flatness Over 125MHz Bandwidth (Note 8) Switching Time Input Return Loss Output Return Loss Group Delay Group-Delay Flatness Over 125MHz Bandwidth Group-Delay Change vs. Attenuation Control Insertion Phase Change vs. Attenuation Control VCTRL = +1.0V to +3.5V VCTRL = +1.0V to +3.5V Peak-to-peak for VCTRL = +1.0V to +3.1V, TC = +25NC From 15dB to 0dB attenuation (Note 9) All gain settings All gain settings Input/output 50I lines deembedded Peak-to-peak VCTRL = +1.0V to +4.0V VCTRL = +1.0V to +4.0V Note 5: Operating outside this range for extended periods may affect device reliability. Limit pin input current to 40mA when VCC is not present (see Table 1 for R4 value). Note 6: Operation outside this range is possible, but with degraded performance of some parameters. See the Typical Operating Characteristics. Note 7: f1 = 1500MHZ, f2 = 1501MHz, -10dBm/tone at attenuator input. Note 8: Guaranteed by design and characterization. Note 9: Switching time is measured from 50% of the control signal to when the RF output settles to Q1dB. 3 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator MAX19790 Typical Operating Characteristics (MAX19790 Evaluation Kit, two attenuators in cascade, VCC = +5.0V, PRF = -10dBm, TC = +25NC, VCTRL = +1.0V, unless otherwise noted.) SUPPLY CURRENT vs. VCC MAX19790 toc01 INPUT MATCH vs. RF FREQUENCY MAX19790 toc02 OUTPUT MATCH vs. RF FREQUENCY MAX19790 toc03 8.0 0 0 SUPPLY CURRENT (mA) TC = +85C 7.5 TC = +25C -10 S11 (dB) TC = +85C TC = -40C -10 S22 (dB) TC = +85C TC = -40C -20 -20 TC = +25C 7.0 TC = -40C -30 TC = +25C -30 6.5 4.750 4.875 5.000 VCC (V) 5.125 5.250 -40 0 1000 2000 3000 4000 RF FREQUENCY (MHz) -40 0 1000 2000 3000 4000 RF FREQUENCY (MHz) INSERTION LOSS vs. RF FREQUENCY MAX19790 toc04 INPUT MATCH vs. VCTRL MAX19790 toc05 OUTPUT MATCH vs. VCTRL 4000MHz -10 250MHz S22 (dB) 500MHz -20 MAX19790 toc06 12 10 INSERTION LOSS (dB) 8 6 4 2 0 0 1000 2000 3000 TC = -40C TC = +85C 0 4000MHz -10 250MHz S11 (dB) 500MHz -20 0 TC = +25C -30 2150MHz -40 4000 1 2 VCTRL (V) 3 950MHz 4 -30 950MHz 2150MHz -40 1 2 VCTRL (V) 3 4 RF FREQUENCY (MHz) ATTENUATION vs. VCTRL MAX19790 toc07 ATTENUATION vs. VCTRL MAX19790 toc08 S21 PHASE CHANGE vs. VCTRL REFERENCED TO INSERTION-LOSS STATE. POSITIVE PHASE = ELECTRICALLY SHORTER. 4000MHz 100 50 0 500MHz -50 250MHz 1 2 VCTRL (V) 3 4 2150MHz MAX19790 toc09 0 250MHz, 500MHz, 950MHz -10 2150MHz -20 S21 (dB) -30 -40 -50 -60 1 2 VCTRL (V) 3 0 -10 -20 S21 (dB) 200 150 fRF = 950MHz 4000MHz -30 -40 -50 -60 1 2 VCTRL (V) 3 4 TC = -40C, +25C, +85C S21 PHASE CHANGE (DEG) 950MHz 4 4 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator Typical Operating Characteristics (continued) (MAX19790 Evaluation Kit, two attenuators in cascade, VCC = +5.0V, PRF = -10dBm, TC = +25NC, VCTRL = +1.0V, unless otherwise noted.) MAX19790 INPUT IP3 vs. VCTRL MAX19790 toc10 INPUT IP3 vs. VCTRL PIN = -10dBm/TONE 950MHz 40 INPUT IP3 (dBm) 35 30 25 20 MAX19790 toc11 45 40 INPUT IP3 (dBm) 35 30 25 TC = +25C 20 1 2 fRF = 950MHz PIN = -10dBm/TONE TC = +85C 45 1500MHz 2150MHz TC = -40C 3 VCTRL (V) 4 1 2 VCTRL (V) 3 4 INPUT IP2 vs. VCTRL MAX19790 toc12 INPUT IP2 vs. VCTRL PIN = -10dBm/TONE 2150MHz MAX19790 toc13 90 80 INPUT IP2 (dBm) 70 60 50 40 1 2 TC = -40C TC = +25C fRF = 950MHz PIN = -10dBm/TONE 90 80 INPUT IP2 (dBm) 70 1500MHz 60 950MHz 50 40 1 2 VCTRL (V) 3 4 TC = +85C 3 VCTRL (V) 4 INPUT P1dB vs. RF FREQUENCY MAX19790 toc14 INPUT P1dB vs. RF FREQUENCY MAX19790 toc15 26 25 INPUT P1dB (dBm) 24 23 22 21 20 950 1350 1750 TC = -40C 26 25 VCC = 5.25V INPUT P1dB (dBm) 24 23 22 21 20 VCC = 4.75V VCC = 5.0V TC = +25C TC = +85C 2150 950 1350 1750 2150 RF FREQUENCY (MHz) RF FREQUENCY (MHz) 5 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator MAX19790 Typical Operating Characteristics (continued) (MAX19790 Evaluation Kit, one attenuator connected, VCC = +5.0V, PRF = -10dBm, TC = +25NC, VCTRL = +1.0V, unless otherwise noted.) SUPPLY CURRENT vs. VCC MAX19790 toc16 INPUT MATCH vs. RF FREQUENCY MAX19790 toc17 OUTPUT MATCH vs. RF FREQUENCY TC = -40C TC = +85C MAX19790 toc18 8.0 0 TC = +85C -10 -20 -30 -40 TC = -40C TC = +25C 0 -10 -20 -30 -40 TC = +25C -50 SUPPLY CURRENT (mA) TC = +85C 7.5 TC = +25C S11 (dB) 7.0 TC = -40C 6.5 4.750 4.875 5.000 VCC (V) 5.125 5.250 -50 0 1000 2000 3000 4000 RF FREQUENCY (MHz) S22 (dB) 0 1000 2000 3000 4000 RF FREQUENCY (MHz) INSERTION LOSS vs. RF FREQUENCY MAX19790 toc19 INPUT MATCH vs. VCTRL MAX19790 toc20 OUTPUT MATCH vs. VCTRL 4000MHz 2150MHz 500MHz 250MHz MAX19790 toc21 8 0 -10 500MHz S11 (dB) 4000MHz 0 -10 -20 -30 -40 INSERTION LOSS (dB) 6 TC = +25C 4 TC = +85C 250MHz 2150MHz S22 (dB) 950MHz -20 -30 -40 -50 1 2 VCTRL (V) 3 4 2 TC = -40C 0 0 1000 2000 3000 4000 RF FREQUENCY (MHz) 950MHz -50 1 2 VCTRL (V) 3 4 ATTENUATION vs. VCTRL MAX19790 toc22 ATTENUATION vs. VCTRL MAX19790 toc23 S21 PHASE CHANGE vs. VCTRL MAX19790 toc24 0 250MHz, 500MHz, 950MHz -5 -10 S21 (dB) -15 4000MHz -20 -25 -30 1 2 VCTRL (V) 3 0 fRF = 950MHz -5 -10 S21 (dB) -15 -20 -25 -30 TC = -40C, +25C, +85C 100 S21 PHASE CHANGE (DEGREES) 75 4000MHz 50 25 0 -25 -50 1 500MHz REFERENCED TO INSERTION-LOSS STATE. POSITIVE PHASE = ELECTRICALLY SHORTER. 2 VCTRL (V) 3 950MHz 2150MHz 250MHz 2150MHz 4 1 2 VCTRL (V) 3 4 4 6 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator Typical Operating Characteristics (continued) (MAX19790 Evaluation Kit, one attenuator connected, VCC = +5.0V, PRF = -10dBm, TC = +25NC, VCTRL = +1.0V, unless otherwise noted.) MAX19790 INPUT IP3 vs. VCTRL MAX19790 toc25 INPUT IP3 vs. VCTRL 1500MHz 40 INPUT IP3 (dBm) 35 30 25 2150MHz 20 950MHz PIN = -10dBm/TONE MAX19790 toc26 45 40 INPUT IP3 (dBm) 35 30 25 TC = +85C 20 1 2 VCTRL (V) 3 TC = +25C TC = -40C fRF = 950MHz PIN = -10dBm/TONE 45 4 1 2 VCTRL (V) 3 4 INPUT IP2 vs. VCTRL fRF = 950MHz PIN = -10dBm/TONE TC = +85C MAX19790 toc27 INPUT IP2 vs. VCTRL PIN = -10dBm/TONE 1500MHz MAX19790 toc28 100 90 INPUT IP2 (dBm) 80 TC = +25C 70 60 50 1 TC = -40C 2 100 90 INPUT IP2 (dBm) 80 70 60 950MHz 50 2150MHz 3 VCTRL (V) 4 1 2 VCTRL (V) 3 4 INPUT P1dB vs. RF FREQUENCY MAX19790 toc29 INPUT P1dB vs. RF FREQUENCY MAX19790 toc30 26 25 INPUT P1dB (dBm) 24 23 22 21 TC = +25C 20 950 1350 1750 TC = +85C TC = -40C 26 25 VCC = 5.25V INPUT P1dB (dBm) 24 23 22 VCC = 4.75V 21 20 VCC = 5.0V 2150 950 1350 1750 2150 RF FREQUENCY (MHz) RF FREQUENCY (MHz) 7 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator MAX19790 Pin Configuration/Functional Diagram GND GND GND GND GND GND GND GND GND TOP VIEW 27 26 25 24 23 22 21 20 19 GND OUT_B GND GND VCC GND GND IN_B GND 28 29 30 31 32 33 34 35 36 MAX19790 ATTEN_B 18 17 16 15 14 13 12 ATTEN_A *EP 11 10 GND GND GND GND GND VCC GND CTRL GND ATTENUATIONCONTROL CIRCUITRY + 1 2 3 4 5 6 7 8 9 OUT_A GND GND IN_A VCC GND GND GND THIN QFN *EXPOSED PAD. GND Pin Description PIN 1, 3, 4, 6, 7, 9, 10, 12, 14-28, 30, 31, 33, 34, 36 2 5, 13, 32 8 NAME GND DESCRIPTION Ground. Connect to the board's ground plane using low-inductance layout techniques. Attenuator A Output. Internally matched to 50I over the operating frequency band. This pin, if used, requires a DC block. If this attenuator is not used, the pin can be left unconnected. Power Supply. Bypass to GND with capacitors and resistors as shown in the Typical Application Circuit. Attenuator A Input. Internally matched to 50I over the operating frequency band. This pin, if used, requires a DC block. If this attenuator is not used, the pin can be left unconnected. Analog Attenuator Control Input. VCC must be present unless using a current-limiting resistor, as noted in the Applications Information section. Limit voltages applied to this pin to a +1.0V to +4.0V range with VCC present to ensure device reliability. Attenuator B Output. Internally matched to 50I over the operating frequency band. This pin, if used, requires a DC block. If this attenuator is not used, the pin can be left unconnected. Attenuator B Input. Internally matched to 50I over the operating frequency band. This pin, if used, requires a DC block. If this attenuator is not used, the pin can be left unconnected. Exposed Pad. Internally connected to GND. Solder evenly to the board's ground plane for proper operation. OUT_A VCC IN_A 11 CTRL 29 35 -- OUT_B IN_B EP 8 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator Detailed Description The MAX19790 is a dual, general-purpose analog voltage variable attenuator (VVA) designed to interface with 50I systems operating in the 250MHz to 4000MHz frequency range. Each attenuator includes a patented control circuit that provides 22dB of attenuation range with a linear control slope of 10dB/V. Both attenuators share a common analog control and can be cascaded together to yield 44dB of total dynamic range, with a combined linear control slope of 20dB/V. connection, to limit the input current to less than 40mA, should the control voltage be applied when VCC is not present. A series resistor of greater than 200I provides complete protection for +5.0V control voltage ranges. Note: To ensure the reliability of the device, limit CTRL input voltages to a +1.0V to +4.0V range when VCC is present. A properly designed PCB is an essential part of any RF/microwave circuit. Keep RF signal lines as short as possible to reduce losses, radiation, and inductance. For best performance, route the ground-pin traces directly to the exposed pad underneath the package. This pad MUST be connected to the ground plane of the board by using multiple vias under the device to provide the best RF and thermal conduction path. Solder the exposed pad on the bottom of the device package to a PCB exposed pad. Proper voltage-supply bypassing is essential for highfrequency circuit stability. Bypass each VCC pin with capacitors placed as close as possible to the device. Place the smallest capacitor closest to the device. See the Typical Application Circuit and Table 1 for details. MAX19790 Layout Considerations Applications Information A single input voltage at the CTRL pin adjusts the attenuation of the device. Up to 22dB of attenuation-control range is provided per attenuator. At the insertion-loss setting, the attenuator's loss is approximately 2.4dB. If a larger attenuation-control range is desired, the second on-chip attenuator can be connected in series to provide an additional 22dB of gain-control range. Note that the CTRL pin simultaneously adjusts both on-chip attenuators. The CTRL input voltage drives a high-impedance load (> 50kI). It is suggested that a current-limiting resistor be included in series with this Analog Attenuation Control Power-Supply Bypassing Table 1. Typical Application Circuit Component Values DESIGNATION C1, C3, C5 QTY 3 DESCRIPTION 220pF Q5%, 50V C0G ceramic capacitors (0402) Murata GRM1555C1H221J 0.01FF Q10%, 25V X7R ceramic capacitors (0402) Murata GRM155R71E103K 1000pF Q5%, 50V C0G ceramic capacitor (0402) Murata GRM1555C1H102J 0.1FF Q10%, 16V X7R ceramic capacitor (0603) Murata GRM188R71C104K Not installed, ceramic capacitor (0603) U1 1 DESIGNATION C9 QTY 1 DESCRIPTION 22pF Q5%, 50V C0G ceramic capacitor (0402) Murata GRM1555C1H220J 10I Q5% resistors (0402) Any 0I resistors (0402) Note: In cases where VCTRL is applied before or removed after VCC, use R4 = 200I. Analog attenuator IC Maxim MAX19790ETX+ Note: U1 has an exposed pad conductor, which requires it to be solder-attached to a grounded pad on the PCB to ensure a proper electrical/thermal design. C2, C4 2 R1, R2 2 C6 1 R3, R4 2 C7 1 C8* 0 *C8 can be used to provide additional filtering. Depending on the external driver used on the CTRL line, this capacitance could slow down the response time. 9 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator MAX19790 The exposed pad (EP) of the device's 36-pin thin QFN package provides a low thermal-resistance path to the die. It is important that the PCB on which the IC is mounted be designed to conduct heat from this contact. In addition, provide the EP with a low-inductance RF ground path for the device. Exposed Pad RF and Thermal Considerations The EP MUST be soldered to a ground plane on the PCB, either directly or through an array of plated via holes. Soldering the pad to ground is also critical for efficient heat transfer. Use a solid ground plane wherever possible. Typical Application Circuit GND GND GND GND GND GND GND GND 20 RFOUT C5 C4 27 26 25 24 23 22 21 GND 19 18 GND OUT_B GND GND 28 29 30 31 32 33 34 35 36 1 2 3 4 5 6 7 8 9 ATTEN_A EP ATTEN_B GND GND GND R3 GND GND VCC GND CTRL GND C8 R4 C9 C6 C7 VCC MAX19790 17 16 15 VCC R2 VCC GND GND IN_B GND ATTENUATIONCONTROL CIRCUITRY 14 13 12 11 10 OUT_A IN_A GND GND GND VCC GND GND C3 GND CTRL R1 VCC C1 RFA C2 RFB* *SCHEMATIC SHOWS CONFIGURATION FOR TWO CASCADED ATTENUATORS. TO USE ATTENUATOR A ONLY MOVE C3 TO CONNECT OUT_A TO RFB. TO USE ATTENUATOR B ONLY MOVE C3 TO CONNECT RFB TO IN_B. 10 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator Chip Information PROCESS: BiCMOS Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 21-0141 MAX19790 36 Thin QFN-EP T3666+2 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 11 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc. |
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