19-5165; Rev 0; 3/10 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator 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 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 Ordering Information PART TEMP RANGE PIN-PACKAGE MAX19790ETX+ -40NC to +85NC 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. Microwave Terrestrial Links Lineup Gain Trim Temperature Compensation Circuits Automatic Level Control (ALC) Transmitter Gain Control Receiver Gain Control General Test Equipment 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. MAX19790 General Description MAX19790 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator 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 SYMBOL CONDITIONS MIN TYP MAX UNITS 5.0 5.25 V 7.3 9.5 mA SUPPLY Supply Voltage VCC Supply Current ICC 4.75 CONTROL INPUT Control Voltage Range VCTRL Control Input Resistance RCTRL (Note 5) 1.0 4.0 50 V kI RECOMMENDED AC OPERATING CONDITIONS PARAMETER RF Frequency Range 2 SYMBOL fRF CONDITIONS (Note 6) MIN 250 TYP MAX UNITS 4000 MHz 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator (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 SYMBOL IL TC = +25NC TYP MAX 950MHz to 1500MHz MIN 4.4 6.3 950MHz to 2150MHz 4.4 7.0 TC = -40NC to +85NC Loss Variation Over Temperature Input P1dB CONDITIONS IP1dB UNITS dB 0.6 dB 23.1 dBm Input Second-Order Intercept Point IIP2 fRF1 + fRF2 term, fRF1 - fRF2 = 1MHz (Note 7) 69.6 dBm Input Third-Order Intercept Point IIP3 fRF1 - fRF2 = 1MHz (Note 7) 36.3 dBm Second Harmonic 2fIN 72 dBc Third Harmonic 3fIN 77 dBc One attenuator, VCTRL = +1.0V to +4.0V, TC = +25NC Attenuation-Control Range AR Two attenuators, VCTRL = +1.0V to +4.0V, TC = +25NC 22 950MHz to 1500MHz 36 44.7 950MHz to 2150MHz 33 44.7 dB Average Attenuation-Control Slope VCTRL = +1.0V to +3.5V 20.0 dB/V Maximum Attenuation-Control Slope VCTRL = +1.0V to +3.5V 30.4 dB/V Attenuation Flatness Over 125MHz Bandwidth (Note 8) Peak-to-peak for VCTRL = +1.0V to +3.1V, TC = +25NC 0.13 0.89 dB Switching Time From 15dB to 0dB attenuation (Note 9) 500 ns Input Return Loss All gain settings 25 dB Output Return Loss All gain settings 21 dB Group Delay Input/output 50I lines deembedded 190 ps Group-Delay Flatness Over 125MHz Bandwidth Peak-to-peak 10 ps Group-Delay Change vs. Attenuation Control VCTRL = +1.0V to +4.0V -175 ps Insertion Phase Change vs. Attenuation Control VCTRL = +1.0V to +4.0V 82 Degrees 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 MAX19790 AC ELECTRICAL CHARACTERISTICS 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 INPUT MATCH vs. RF FREQUENCY TC = +85C 7.0 -10 S22 (dB) TC = -40C -20 MAX19790 toc03 -10 0 MAX19790 toc02 MAX19790 toc01 TC = +85C TC = +25C 7.5 OUTPUT MATCH vs. RF FREQUENCY 0 S11 (dB) SUPPLY CURRENT (mA) 8.0 TC = +85C TC = -40C -20 TC = -40C -30 TC = +25C -30 TC = +25C 5.125 -40 5.250 -40 1000 0 VCC (V) 2000 3000 4000MHz -10 S11 (dB) TC = +85C 4000 OUTPUT MATCH vs. VCTRL 0 4000MHz -10 250MHz TC = +25C 250MHz 500MHz -20 500MHz -20 4 -30 -30 950MHz 2150MHz 950MHz -40 0 2000 3000 4000 2 3 -40 4 ATTENUATION vs. VCTRL 250MHz, 500MHz, 950MHz -10 fRF = 950MHz -10 2150MHz S21 (dB) -20 4000MHz -30 -40 -40 -50 -50 -60 -60 1 2 3 VCTRL (V) 4 4 S21 PHASE CHANGE vs. VCTRL ATTENUATION vs. VCTRL -20 3 VCTRL (V) 0 MAX19790 toc07 0 -30 2 1 VCTRL (V) RF FREQUENCY (MHz) TC = -40C, +25C, +85C 200 S21 PHASE CHANGE (DEGREES) 1000 1 MAX19790 toc08 0 2150MHz REFERENCED TO INSERTION-LOSS STATE. POSITIVE PHASE = ELECTRICALLY SHORTER. 150 MAX19790 toc09 TC = -40C 2 4 1000 0 RF FREQUENCY (MHz) 0 MAX19790 toc04 10 INSERTION LOSS (dB) 4000 INPUT MATCH vs. VCTRL INSERTION LOSS vs. RF FREQUENCY 6 3000 RF FREQUENCY (MHz) 12 8 2000 MAX19790 toc06 5.000 S22 (dB) 4.875 MAX19790 toc05 6.5 4.750 S21 (dB) MAX19790 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator 2150MHz 4000MHz 100 50 950MHz 0 500MHz 250MHz -50 1 2 3 VCTRL (V) 4 1 2 3 VCTRL (V) 4 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator 35 30 40 35 30 1500MHz 2150MHz TC = -40C 25 PIN = -10dBm/TONE 950MHz INPUT IP3 (dBm) TC = +85C MAX19790 toc10 fRF = 950MHz PIN = -10dBm/TONE 40 INPUT IP3 (dBm) INPUT IP3 vs. VCTRL 45 MAX19790 toc11 INPUT IP3 vs. VCTRL 45 25 TC = +25C 20 20 2 4 3 1 2 VCTRL (V) INPUT IP2 vs. VCTRL fRF = 950MHz PIN = -10dBm/TONE TC = +25C 70 60 2 1500MHz 60 50 40 1 70 950MHz TC = +85C TC = -40C 50 PIN = -10dBm/TONE 2150MHz 80 INPUT IP2 (dBm) 80 INPUT IP2 (dBm) INPUT IP2 vs. VCTRL 90 MAX19790 toc12 90 40 4 3 1 2 VCTRL (V) INPUT P1dB vs. RF FREQUENCY INPUT P1dB vs. RF FREQUENCY TC = -40C MAX19790 toc15 26 MAX19790 toc14 26 25 INPUT P1dB (dBm) INPUT P1dB (dBm) VCC = 5.25V 24 23 22 TC = +25C 21 4 3 VCTRL (V) 25 4 3 VCTRL (V) MAX19790 toc13 1 24 VCC = 5.0V 23 VCC = 4.75V 22 21 TC = +85C 20 20 950 1350 1750 RF FREQUENCY (MHz) 2150 950 1350 1750 2150 RF FREQUENCY (MHz) 5 MAX19790 Typical Operating Characteristics (continued) (MAX19790 Evaluation Kit, two attenuators in cascade, VCC = +5.0V, PRF = -10dBm, TC = +25NC, VCTRL = +1.0V, unless otherwise noted.) Typical Operating Characteristics (continued) (MAX19790 Evaluation Kit, one attenuator connected, VCC = +5.0V, PRF = -10dBm, TC = +25NC, VCTRL = +1.0V, unless otherwise noted.) INPUT MATCH vs. RF FREQUENCY 7.0 S22 (dB) -20 -30 TC = -40C -10 TC = +25C TC = +25C 7.5 0 MAX19790 toc17 MAX19790 toc16 TC = +85C -10 S11 (dB) TC = +85C -20 -30 TC = -40C -40 -40 TC = -40C 4.875 5.000 5.125 5.250 -50 0 1000 VCC (V) INSERTION LOSS vs. RF FREQUENCY 3000 4000 0 1000 MAX19790 toc19 6 4000MHz -10 250MHz 500MHz TC = +85C 2 4000MHz -10 2150MHz 2150MHz -20 -30 -40 TC = -40C -30 -40 3000 4000 1 2 RF FREQUENCY (MHz) -10 4000MHz -15 -20 -20 -25 -25 TC = -40C, +25C, +85C -30 -30 2 3 VCTRL (V) 6 fRF = 950MHz -5 S21 (dB) 2150MHz 4 1 2 3 VCTRL (V) 3 4 S21 PHASE CHANGE vs. VCTRL -10 -15 1 2 1 VCTRL (V) 0 MAX19790 toc22 250MHz, 500MHz, 950MHz -5 4 ATTENUATION vs. VCTRL ATTENUATION vs. VCTRL 0 3 VCTRL (V) 4 100 MAX19790 toc24 2000 -50 S21 PHASE CHANGE (DEGREES) 1000 950MHz -50 MAX19790 toc23 0 250MHz 500MHz -20 950MHz 0 4000 3000 OUTPUT MATCH vs. VCTRL 0 S22 (dB) TC = +25C 2000 RF FREQUENCY (MHz) INPUT MATCH vs. VCTRL 0 S11 (dB) INSERTION LOSS (dB) 2000 RF FREQUENCY (MHz) 8 4 TC = +25C -50 MAX19790 toc20 6.5 4.750 MAX19790 toc21 SUPPLY CURRENT (mA) TC = +85C OUTPUT MATCH vs. RF FREQUENCY 0 MAX19790 toc18 SUPPLY CURRENT vs. VCC 8.0 S21 (dB) MAX19790 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator 75 4000MHz 50 2150MHz 950MHz 25 250MHz 0 500MHz -25 REFERENCED TO INSERTION-LOSS STATE. POSITIVE PHASE = ELECTRICALLY SHORTER. -50 1 2 3 VCTRL (V) 4 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator INPUT IP3 vs. VCTRL 35 30 TC = +25C TC = -40C 25 PIN = -10dBm/TONE 1500MHz 40 INPUT IP3 (dBm) 35 950MHz 30 25 2150MHz TC = +85C 20 20 2 1 3 4 2 1 VCTRL (V) INPUT IP2 vs. VCTRL fRF = 950MHz PIN = -10dBm/TONE TC = +85C 80 TC = +25C 70 PIN = -10dBm/TONE 90 INPUT IP2 (dBm) INPUT IP2 (dBm) 90 4 INPUT IP2 vs. VCTRL 100 MAX19790 toc27 100 3 VCTRL (V) 60 1500MHz MAX19790 toc28 INPUT IP3 (dBm) 40 MAX19790 toc25 fRF = 950MHz PIN = -10dBm/TONE 45 MAX19790 toc26 INPUT IP3 vs. VCTRL 45 80 70 2150MHz 60 950MHz TC = -40C 1 50 2 3 4 1 2 VCTRL (V) INPUT P1dB vs. RF FREQUENCY INPUT P1dB vs. RF FREQUENCY TC = -40C 25 23 22 VCC = 5.0V VCC = 5.25V INPUT P1dB (dBm) INPUT P1dB (dBm) 25 24 23 22 VCC = 4.75V TC = +85C 21 4 26 MAX19790 toc29 26 24 3 VCTRL (V) MAX19790 toc30 50 21 TC = +25C 20 20 950 1350 1750 RF FREQUENCY (MHz) 2150 950 1350 1750 2150 RF FREQUENCY (MHz) 7 MAX19790 Typical Operating Characteristics (continued) (MAX19790 Evaluation Kit, one attenuator connected, VCC = +5.0V, PRF = -10dBm, TC = +25NC, VCTRL = +1.0V, unless otherwise noted.) 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator GND GND GND GND GND GND GND TOP VIEW GND GND MAX19790 Pin Configuration/Functional Diagram 27 26 25 24 23 22 21 20 19 GND GND 30 VCC GND 32 GND IN_B 34 GND 36 MAX19790 29 ATTEN_B 31 ATTENUATIONCONTROL CIRCUITRY 33 18 GND 17 16 GND GND 15 GND 14 11 GND VCC GND CTRL 10 GND 13 12 ATTEN_A 35 *EP 2 3 4 5 6 7 VCC GND GND GND 1 OUT_A GND GND + 8 9 GND 28 IN_A GND OUT_B THIN QFN *EXPOSED PAD. Pin Description 8 PIN NAME 1, 3, 4, 6, 7, 9, 10, 12, 14-28, 30, 31, 33, 34, 36 FUNCTION GND 2 OUT_A 5, 13, 32 VCC Power Supply. Bypass to GND with capacitors and resistors as shown in the Typical Application Circuit. 8 IN_A 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. 11 CTRL 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. 29 OUT_B 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. 35 IN_B 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. -- EP Exposed Pad. Internally connected to GND. Solder evenly to the board's ground plane for proper operation. 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. 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator 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 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. Applications Information Analog Attenuation Control 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 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. Layout Considerations 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. Power-Supply Bypassing 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. Table 1. Typical Application Circuit Component Values DESIGNATION QTY DESCRIPTION C1, C3, C5 3 220pF Q5%, 50V C0G ceramic capacitors (0402) Murata GRM1555C1H221J C2, C4 2 0.01FF Q10%, 25V X7R ceramic capacitors (0402) Murata GRM155R71E103K C6 1 1000pF Q5%, 50V C0G ceramic capacitor (0402) Murata GRM1555C1H102J C7 1 0.1FF Q10%, 16V X7R ceramic capacitor (0603) Murata GRM188R71C104K C8* 0 Not installed, ceramic capacitor (0603) DESIGNATION QTY C9 1 22pF Q5%, 50V C0G ceramic capacitor (0402) Murata GRM1555C1H220J R1, R2 2 10I Q5% resistors (0402) Any 2 0I resistors (0402) Note: In cases where VCTRL is applied before or removed after VCC, use R4 = 200I. 1 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. R3, R4 U1 DESCRIPTION *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 MAX19790 Detailed Description 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. 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. 27 VCC GND GND IN_B GND GND GND GND GND GND GND GND 19 18 29 17 MAX19790 30 16 ATTEN_B 31 15 ATTENUATIONCONTROL CIRCUITRY 32 14 13 33 34 EP ATTEN_A 12 35 11 36 10 OUT_A 2 3 4 5 6 7 8 9 GND GND VCC GND R3 GND C7 GND C6 VCC GND C9 CTRL GND C8 R4 CTRL R1 C1 RFA VCC RFB* 20 28 1 C3 21 GND VCC R2 22 IN_A GND 23 GND GND C4 24 GND OUT_B 25 VCC C5 26 GND GND GND RFOUT GND GND Typical Application Circuit GND MAX19790 250MHz to 4000MHz Dual, Analog Voltage Variable Attenuator C2 *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 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. 36 Thin QFN-EP T3666+2 21-0141 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) 2010 Maxim Integrated Products 11 Maxim is a registered trademark of Maxim Integrated Products, Inc. MAX19790 Chip Information PROCESS: BiCMOS