19-3445; Rev 1; 6/05 Broadband Variable-Gain Amplifiers KIT ATION EVALU E L B AVAILA The MAX3537/MAX3538 broadband RF variable-gain amplifiers (VGA) are designed for digital and OpenCableTM set-tops and televisions. These devices feature a unique design that integrates a dual-band (UHF and VHF) input and a low-noise, variable-gain amplifier. The integrated RF VGA covers a 10MHz to 1GHz input frequency range and provides 22dB of gain-control range. The MAX3538 is intended for the most difficult signal conditions where performance is critical. The external pullup inductor improves IIP2 and IIP3 while also increasing gain for better sensitivity. The MAX3537 does not need an external pullup inductor and is ideal for low-power applications with less demanding receiver distortion requirements such as smaller TVs using indoor antennas. The MAX3537/MAX3538 are specified for operation in the 0C to +85C temperature range and are available in 4mm x 4mm, 12-pin thin QFN packages with exposed paddle (EP). Applications Features Low-Noise VGA Eliminates PIN Attenuator 22dB Gain-Control Range Low Noise Figure: 5dB at Maximum Gain Setting High Linearity: +19dBm IIP3 (MAX3538) at Maximum Gain Setting Low Power Consumption: <200mW (MAX3537) Available in a 4mm x 4mm, 12-Pin Thin QFN Package Ordering Information TEMP RANGE PART PKG CODE PIN-PACKAGE OpenCable Set-Top Boxes and Televisions MAX3537UTC 0C to +85C 12 Thin QFN-EP* T1244-3 Digital Set-Top Boxes MAX3537UTC+ 0C to +85C 12 Thin QFN-EP* T1244-3 Media Gateways MAX3538UTC 0C to +85C 12 Thin QFN-EP* T1244-3 Digital Terrestrial Receivers MAX3538UTC+ 0C to +85C 12 Thin QFN-EP* T1244-3 TV IF Strips *EP = Exposed paddle. +Denotes lead-free package. Pin Configuration/ Functional Diagram 2 UHF_SHUNT 3 RF_GND2 GND 10 MAX3537/3538 4 5 6 SHDN RF_GND1 11 SEL_UHF 1 12 RBIAS UHF_IN VHF_IN OpenCable is a trademark of Cable Television Laboratories, Inc. 9 LNAOUT 8 VCC 7 RFAGC ________________________________________________________________ Maxim Integrated Products 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. 1 MAX3537/MAX3538 General Description MAX3537/MAX3538 Broadband Variable-Gain Amplifiers ABSOLUTE MAXIMUM RATINGS VCC to GND ...........................................................-0.3V to +5.5V RFAGC, UHF_IN, SEL_UHF, VHF_IN, SHDN, RBIAS, RF_GND1, RF_GND2, UHF_SHUNT to GND....................................................-0.3V to (VCC + 0.3V) LNAOUT Short-Circuit Duration..............................................10s UHFIN, VHFIN Maximum RF Input Power.........................14dBm Continuous Power Dissipation (TA = +70C) 12-Pin Thin QFN (derate 16.9mW/C above +70C)............................................................1349mW Operating Temperature Range...............................0C to +85C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C CAUTION! ESD SENSITIVE DEVICE 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 (MAX3537/MAX3538 EV kit, VCC = 4.75V to 5.25V, no RF signal applied, TA = 0C to +85C, unless otherwise noted. Typical values are at VCC = 5V, RBIAS = 11.8k (MAX3537) or 9.1k (MAX3538), TA = +25C, unless otherwise noted.) (Note 1) PARAMETER CONDITIONS Supply Voltage Supply Current MIN Operational mode RFAGC Control Voltage (Note 2) MAX UNITS 5.25 V MAX3537 38 45.8 MAX3538 48 58 Standby mode (VENABLE = VSEL_UHF = 0.1V) RFAGC Input Bias Current TYP 4.75 VRFAGC = 1V and 3V 2 -50 Maximum gain 100 A +50 A 3 Minimum gain 1 0.3 x VCC Input Logic-Level Low 0.7 x VCC Input Logic-Level High mA V V V AC ELECTRICAL CHARACTERISTICS (MAX3537) (MAX3537 EV kit, VCC = 4.75V to 5.25V, TA = 0C to +85C, unless otherwise noted. Typical values are at VCC = 5V, RBIAS = 11.8k, TA = +25C, unless otherwise noted.) (Note 1) PARAMETER CONDITIONS Operating Frequency Range Input Return Loss MIN TYP 50 Diplex filter included, worst case across band, any gain setting (Note 2) Input Power Range Per Channel 4.3 -35 Maximum gain 7.7 9.6 Linear Gain-Control Range Measured at 50MHz, difference between maximum and minimum gain 19.2 23.1 Gain Flatness From 50MHz to 878MHz, VRFAGC = 3V (Note 2) Noise Figure Maximum gain, diplexer loss included 2 UNITS 878 MHz 8.5 Voltage Gain Input 2nd-Order Intercept Point MAX dB +50 dBmV 12.7 dB dB 2.8 5 Maximum gain, VRFAGC = 3V (Notes 2, 3) 21.6 26 Minimum gain, VRFAGC = 1V 42.5 48 _______________________________________________________________________________________ dB dB dBm Broadband Variable-Gain Amplifiers (MAX3537 EV kit, VCC = 4.75V to 5.25V, TA = 0C to +85C, unless otherwise noted. Typical values are at VCC = 5V, RBIAS = 11.8k, TA = +25C, unless otherwise noted.) (Note 1) PARAMETER Input 3rd-Order Intercept Point MIN TYP Maximum gain, VRFAGC = 3V (Note 4) CONDITIONS 12.7 17 Minimum gain, VRFAGC = 1V (Note 2) 28.2 33 0 1.9 1dB Compression Point Maximum gain (Note 2) Isolation Shutdown mode, 50MHz to 878MHz, RF input to RF output Port to port 23 Output Return Loss Unbalanced 75 load 10 MAX UNITS dBm dBm 37 dBc dB AC ELECTRICAL CHARACTERISTICS (MAX3538) (MAX3538 EV kit, VCC = 4.75V to 5.25V, TA = 0C to +85C, unless otherwise noted. Typical values are at VCC = 5V, RBIAS = 9.1k, TA = +25C, unless otherwise noted.) (Note 1) PARAMETER CONDITIONS Operating Frequency Range TYP 50 Diplex filter included, worst case across band, any gain setting (Note 2) Input Return Loss MIN Input Power Range Per Channel 5.4 -35 Maximum gain 9.7 12.4 Linear Gain-Control Range Measured at 50MHz, difference between maximum and minimum gain 19 23 Gain Flatness From 50MHz to 878MHz, VRFAGC = 3V (Note 2) Noise Figure Maximum gain, diplexer loss included 5 34 Minimum gain, VRFAGC = 1V 47.6 53 Maximum gain, VRFAGC = 3V (Note 4) 15.4 19 Minimum gain, VRFAGC = 1V (Note 2) 30 33 1dB Compression Point Maximum gain. (Note 2) 2.2 4 Isolation Shutdown mode, 50MHz to 878MHz, RF input to RF output Port to port 24 Output Return Loss Unbalanced 75 load 10 Input 3rd-Order Intercept Point Note 1: Note 2: Note 3: Note 4: MHz dB +50 dBmV 15.7 dB dB 2.9 27 Input 2nd-Order Intercept Point UNITS 878 8.5 Voltage Gain Maximum gain, VRFAGC = 3V (Notes 2, 3) MAX 41 dB dB dBm dBm dBm dBc dB Guaranteed by production test at TA = +25C and +85C and does not include diplex filter loss, unless otherwise noted. Guaranteed by design and characterization from TA = 0C to +85C. Tested with input tones at 210MHz and 660MHz at -12dBm/tone. Diplexer is not included. Tested with input tones at 760MHz and 810MHz at -12dBm/tone. Diplexer is not included. _______________________________________________________________________________________ 3 MAX3537/MAX3538 AC ELECTRICAL CHARACTERISTICS (MAX3537) (continued) Typical Operating Characteristics (MAX3537 EV kit with diplex filter removed, VCC = 5V, VRFAGC = 3V, TA = +25C, unless otherwise noted.) MAX3537 SUPPLY CURRENT vs. SUPPLY VOLTAGE GAIN vs. FREQUENCY 16 TA = +25C 14 TA = +85C 38 8 6 -10 -15 0 4.9 5.0 5.1 5.2 10 120 230 340 450 560 670 780 890 1000 FREQUENCY (MHz) 5.3 SUPPLY VOLTAGE (V) NOISE FIGURE vs. FREQUENCY 10 8 TA = +85C 7 TA = +25C 5 fRF = 50MHz 30 NOISE FIGURE (dB) 9 IIP2 vs. GAIN-CONTROL VOLTAGE 70 65 60 25 55 IIP2 (dBm) 11 VRFAGC (V) NOISE FIGURE vs. GAIN 35 MAX3537 toc04 12 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 MAX3537 toc06 4.8 MAX3537 toc05 4.7 20 15 50 45 40 35 10 4 30 5 0 2 -5 0 5 10 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 VRFAGC (V) OUTPUT RETURN LOSS vs. FREQUENCY INPUT RETURN LOSS vs. FREQUENCY 35 30 25 20 A 5.00 B 10.00 C 15.00 20.00 D 25.00 f1 = 400MHz f2 = 450MHz MAX3537 toc08 WITH DIPLEXER INPUT RETURN LOSS (dB) 40 0 F E 0 2.00 OUTPUT RETURN LOSS (dB) MAX3537 toc07 45 -10 GAIN (dB) IIP3 vs. VRFAGC 50 20 -15 10 120 230 340 450 560 670 780 890 1000 FREQUENCY (MHz) f1 = 400MHz f2 = 450MHz 25 fRF = 878MHz WITH DIPLEXER 4.00 A 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 VRFAGC (V) B C 6.00 8.00 10.00 12.00 14.00 F 16.00 E D 18.00 10 MAX3537 toc09 TA = 0C 3 4 fRF = 50MHz 2 30 15 0 -5 TA = +85C TA = +25C 4 32 NOISE FIGURE (dB) 5 10 34 6 fRF = 878MHz TA = 0C 12 36 10 GAIN (dB) 40 MAX3537 toc03 18 GAIN (dB) SUPPLY CURRENT (mA) 42 15 MAX3537 toc02 TA = 0C 44 GAIN vs. GAIN-CONTROL VOLTAGE 20 MAX3537 toc01 46 IIP3 (dBm) MAX3537/MAX3538 Broadband Variable-Gain Amplifiers 20.00 30.00 50 170 290 410 530 650 770 890 FREQUENCY (MHz) A: TA = +85C, UHF_IN ENABLED D: TA = +85C, VHF_IN ENABLED B: TA = +25C, UHF_IN ENABLED E: TA = +25C, VHF_IN ENABLED C: TA = 0C, UHF_IN ENABLED F: TA = 0C, VHF_IN ENABLED 50 170 290 410 530 650 770 890 FREQUENCY (MHz) A: TA = +85C, UHF_IN ENABLED D: TA = +85C, VHF_IN ENABLED B: TA = +25C, UHF_IN ENABLED E: TA = +25C, VHF_IN ENABLED C: TA = 0C, UHF_IN ENABLED F: TA = 0C, VHF_IN ENABLED _______________________________________________________________________________________ Broadband Variable-Gain Amplifiers MAX3537 CURRENT IIP3 17 35 15 33 13 31 11 27 25 11.8 12.6 13.4 14.2 -20.00 -25.00 WITH DIPLEXER -30.00 12 -35.00 10 8 6 -40.00 -45.00 -50.00 -55.00 4 9 f1 = 400MHz f2 = 450MHz PIN = -12dBm/tone fRF = 400MHz 21 19 37 29 14 GAIN (dB) 39 16 23 IIP3 (dBm) SUPPLY CURRENT (mA) 41 25 MAX3537 toc11 43 GAIN (dB) MAX3537 toc10 45 SHUTDOWN ISOLATION vs. FREQUENCY GAIN vs. RBIAS MAX3537 toc12 SUPPLY CURRENT AND IIP3 vs. RBIAS -60.00 7 2 5 0 -65.00 11.8 15.0 12.6 13.4 14.2 15.0 -70.00 10 120 230 340 450 560 670 780 890 1000 FREQUENCY (MHz) RBIAS (k) RBIAS (k) Typical Operating Characteristics (MAX3538 EV kit with diplex filter removed, VCC = 5V, VRFAGC = 3V, TA = +25C, unless otherwise noted.) MAX3538 15 14 TA = +25C 10 fRF = 878MHz 13 TA = +85C 48 46 5 12 11 10 TA = +85C TA = +25C GAIN (dB) 50 15 MAX3538 toc02 MAX3538 toc01 TA = 0C 52 16 GAIN (dB) SUPPLY CURRENT (mA) 54 GAIN vs. GAIN-CONTROL VOLTAGE GAIN vs. FREQUENCY 56 TA = 0C 9 44 8 42 MAX3538 toc03 SUPPLY CURRENT vs. SUPPLY VOLTAGE 0 -5 fRF = 50MHz -10 7 40 -15 6 4.7 4.8 4.9 5.0 5.1 SUPPLY VOLTAGE (V) 5.2 5.3 10 120 230 340 450 560 670 780 890 1000 FREQUENCY (MHz) 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 VRFAGC (V) _______________________________________________________________________________________ 5 MAX3537/MAX3538 Typical Operating Characteristics (continued) (MAX3537 EV kit with diplex filter removed, VCC = 5V, VRFAGC = 3V, TA = +25C, unless otherwise noted.) Typical Operating Characteristics (continued) (MAX3538 EV kit with diplex filter removed, VCC = 5V, VRFAGC = 3V, TA = +25C, unless otherwise noted.) MAX3538 NOISE FIGURE vs. FREQUENCY NOISE FIGURE vs. GAIN 8 NOISE FIGURE (dB) TA = +85C 7 TA = +25C 6 TA = 0C 5 65 60 20 fRF = 50MHz 15 fRF = 878MHz 45 10 5 f1 = 400MHz f2 = 450MHz 35 3 0 10 120 230 340 450 560 670 780 890 1000 FREQUENCY (MHz) -10 -5 0 5 10 15 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 GAIN (dB) VRFAGC (V) INPUT RETURN LOSS vs. FREQUENCY WITH DIPLEXER A, B, C 5.00 INPUT RETURN LOSS (dB) 45 40 35 30 25 20 10.00 15.00 F 20.00 E WITH DIPLEXER D 25.00 f1 = 400MHz f2 = 450MHz OUTPUT RETURN LOSS vs. FREQUENCY 0 OUTPUT RETURN LOSS (dB) MAX3538 toc07 0 MAX3538 toc08 IIP3 vs. VRFAGC 50 15 30 -15 10.00 15.00 F 20.00 E D 30.00 50 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 VRFAGC (V) 650 21 770 890 50 170 290 410 530 650 770 890 SHUTDOWN ISOLATION vs. FREQUENCY 15 13 36 11 34 9 f1 = 400MHz f2 = 450MHz PIN = -12dBm/tone 30 11.8 -20.00 WITH DIPLEXER -25.00 -30.00 14 IIP3 (dBm) 40 CURRENT fRF = 400MHz 16 19 17 10.9 18 23 42 RBIAS (k) 530 -35.00 12 GAIN (dB) IIP3 10.0 410 MAX3538 toc11 46 25 GAIN (dB) 48 38 290 GAIN vs. RBIAS MAX3538 toc10 50 44 170 FREQUENCY (MHz) FREQUENCY (MHz) A: TA = +85C, UHF_IN ENABLED D: TA = +85C, VHF_IN ENABLED A: TA = +85C, UHF_IN ENABLED D: TA = +85C, VHF_IN ENABLED B: TA = +25C, UHF_IN ENABLED E: TA = +25C, VHF_IN ENABLED B: TA = +25C, UHF_IN ENABLED E: TA = +25C, VHF_IN ENABLED C: TA = 0C, UHF_IN ENABLED F: TA = 0C, VHF_IN ENABLED C: TA = 0C, UHF_IN ENABLED F: TA = 0C, VHF_IN ENABLED SUPPLY CURRENT AND IIP3 vs. RBIAS 9.1 A, B, C 5.00 25.00 30.00 10 32 MAX3538 toc09 2 IIP2 (dBm) 50 40 4 6 55 MAX3538 toc12 NOISE FIGURE (dB) 9 MAX3538 toc06 25 IIP2 (dBm) 10 70 MAX3538 toc05 11 IIP2 vs. VRFAGC 30 MAX3538 toc04 12 SUPPLY CURRENT (mA) MAX3537/MAX3538 Broadband Variable-Gain Amplifiers 10 8 -40.00 -45.00 -50.00 -55.00 6 7 4 5 2 -60.00 -65.00 -70.00 9.1 10.0 10.9 RBIAS (k) 11.8 10 120 230 340 450 560 670 780 890 FREQUENCY (MHz) _______________________________________________________________________________________ Broadband Variable-Gain Amplifiers PIN NAME 1 UHF_IN FUNCTION 2 RF_GND1 3 UHF_SHUNT UHF Input. This input is terminated into 75 when not selected. First RF Ground. Connect a 1000pF capacitor from RF_GND1 to GND. Do not connect RF_GND1 to RF_GND2. UHF Shunt. Connects to GND when SEL_UHF is low, high impedance when SEL_UHF is high. 4 RBIAS Amplifier Bias. Connect an 11.8k 1% (MAX3537) or 9.1k 1% (MAX3538) resistor from RBIAS to GND. 5 SEL_UHF Band-Select Input. Selects between the UHF and VHF inputs. Logic low to select VHF, logic high to select UHF. 6 SHDN 7 RFAGC 8 VCC 9 LNAOUT 10 GND Shutdown. Logic low to put the device in standby mode. Logic high for normal operation. Automatic Gain-Control Input. Accepts a DC voltage from 1V (minimum gain) to 3V (maximum gain). Supply Voltage. Bypass to GND with 47pF and 1000pF capacitors placed as close to the device as possible. RF Output. Requires a DC-blocking capacitor. The MAX3538 requires a 560nH pullup inductor from LNAOUT to VCC. Ground 11 RF_GND2 12 VHF_IN EP GND Second RF Ground. Connect a 1000pF capacitor from RF_GND2 to GND. Do not connect RF_GND2 to RF_GND1. VHF Input. This input is terminated into approximately 75 when not selected. Exposed Paddle. Solder evenly to the board's ground plane for proper operation. Detailed Description The MAX3537/MAX3538 variable-gain amplifiers are designed for US digital television applications, specifically to meet ATSC's recommended receiver requirements. The MAX3538 uses an external pullup inductor for maximum linearity and gain and is ideal for performance-driven applications. The MAX3537 does not require an external pullup inductor and requires 10mA less current than the MAX3538. This results in slightly lower linearity and gain but is an acceptable option for cost- and/or power-sensitive applications. The two parts are otherwise identical and can use the same layout and application schematic except for the pullup inductor and RBIAS resistor. Dual-Band Inputs The MAX3537/MAX3538 feature two RF inputs, one for the VHF band (50MHz to 230MHz) and one for the UHF band (470MHz to 810MHz). An external diplex filter attenuates the undesired band. The diplex filter is easily implemented with discrete components, see the Typical Application Circuit for typical component values. Selection between the two inputs is achieved with a single digital input, SEL_UHF. See Table 1 for a description of SEL_UHF operation. The VHF and UHF inputs are terminated into approximately 75 when not selected. Table 1. SEL_UHF Operation SEL_UHF FUNCTION 0 Receive VHF channels (50MHz to 230MHz) or cable channels below approximately 305MHz. 1 Receive UHF channels (470MHz to 810MHz) or cable channels above approximately 305MHz. Broadband Variable-Gain Amplifier (VGA) The MAX3537/MAX3538 integrate a broadband lownoise variable-gain amplifier. The MAX3538 VGA has an open-collector output and requires a pullup inductor to VCC, while the MAX3537 has an internal pullup to VCC. Both the MAX3537 and MAX3538 outputs require a DC-blocking capacitor. The MAX3537/MAX3538 provide a 22dB gain-control range for increased system linearity. A DC voltage applied at the RFAGC pin controls the devices' overall gain, and can range from 1V to 3V with 3V providing the maximum gain setting. _______________________________________________________________________________________ 7 MAX3537/MAX3538 Pin Description MAX3537/MAX3538 Broadband Variable-Gain Amplifiers TYPICAL APPLICATION CIRCUIT FREQUENCY RESPONSE TYPICAL APPLICATION CIRCUIT NOISE FIGURE (MAX3537) 20.00 15.00 10 A B 9 5.00 D 0 -5.00 6 4 -15.00 UHF_IN ENABLED 3 -20.00 10 120 230 340 450 560 670 780 890 1000 FREQUENCY (MHz) A: MAX3538, VHF_IN ENABLED C: MAX3538, UHF_IN ENABLED B: MAX3537, VHF_IN ENABLED D: MAX3537, UHF_IN ENABLED Figure 1. Frequency Response of the MAX3537/MAX3538 Typical Application Circuit TYPICAL APPLICATION CIRCUIT NOISE FIGURE (MAX3538) 10 VHF_IN ENABLED 8 7 NF (dB) 7 5 -10.00 9 VHF_IN ENABLED 8 C NF (dB) GAIN (dB) 10.00 6 5 2 10 120 230 340 450 560 670 780 890 1000 FREQUENCY (MHz) Figure 2. Noise Figure of MAX3537 Typical Application Circuit filter attenuates the undesired channels, improving second-order distortion performance. Terrestrial + Cable Television Applications Television receivers having one RF input or multiple inputs that must receive cable and terrestrial channels must cover a 50MHz to 860MHz frequency range. The diplex filter must allow reception within this range while still providing attenuation of the undesired band. The Typical Application Circuit provides acceptable gain and noise figure performance over the diplexer transition band between VHF and UHF, see Figures 1 and 3. 4 UHF_IN ENABLED 3 2 10 120 230 340 450 560 670 780 890 1000 FREQUENCY (MHz) Figure 3. Noise Figure of MAX3538 Typical Application Circuit Applications Information Terrestrial Television Applications Television receivers having dedicated RF inputs for cable and terrestrials reception can optimize the terrestrial path to better meet the difficult requirements recommended by ATSC. For dedicated terrestrial reception, the diplex filter is optimized for reception of VHF and UHF channels (50MHz to 230MHz, and 470MHz to 810MHz). The diplex 8 Layout Considerations The EV kit serves as a guide for PC board layout. Keep RF signal lines as short as possible to minimize losses and radiation. Use controlled impedance on all highfrequency traces. For proper operation, solder the exposed paddle evenly to the ground plane. Use abundant vias beneath the exposed paddle for maximum heat dissipation. Use abundant ground vias between RF traces to minimize undesired coupling. Bypass VCC to ground with 47nF and 1000nF capacitors placed as close to the pin as possible, with the 47nF capacitor closest to the device. Chip Information TRANSISTOR COUNT: 1982 PROCESS: BiCMOS _______________________________________________________________________________________ Broadband Variable-Gain Amplifiers L3 56nH C12 4.7pF 12 C1 6.8pF C2 6.8pF RFIN L2 8.2nH UHF_IN GND C10 10pF C8 1000pF RF_GND2 L4 56nH VHF_IN C11 1000pF 11 C7 1000pF 10 1 TV TUNER INPUT 9 LNAOUT L2* VCC L1 22nH RF_GND1 C3 1000pF UHF_SHUNT 2 8 MAX3537/3538 3 7 VCC RFAGC C5 47pF C6 1000pF R2 20k VRFAGC RBIAS * MAX3537 MAX3538 R1 11.8k 9.1k L2 OPEN 560nH R1* 6 C4 100nF SHDN 5 SEL_UHF 4 ENABLE SEL_UHF Figure 4. Typical Application Circuit _______________________________________________________________________________________ 9 MAX3537/MAX3538 Typical Application Circuit 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.) 24L QFN THIN.EPS MAX3537/MAX3538 Broadband Variable-Gain Amplifiers PACKAGE OUTLINE, 12, 16, 20, 24, 28L THIN QFN, 4x4x0.8mm 21-0139 10 ______________________________________________________________________________________ D 1 2 Broadband Variable-Gain Amplifiers PACKAGE OUTLINE, 12, 16, 20, 24, 28L THIN QFN, 4x4x0.8mm 21-0139 D 2 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 ____________________ 11 (c) 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc. MAX3537/MAX3538 Package Information (continued) (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.)