ARA05050

ARA05050 Reverse Amplifier with Step Attenuator Data Sheet - Rev 2.2 FEATURES • • • • • • • • Low Cost Integrated Monolothic GaAs Amplifier With Step Attenuator Attenuation Range: 0-30 dB, Adjustable In 2dB Increments Via a 4 Wire Parallel Control Meets DOCSIS Distortion Requirements at +58dBmV Output Signal Level Low Distortion and Low Noise Low Signal toNoise Ratio at All Gain Levels Frequency Range: 5-100 MHz 5 Volt Operation RoHS-Compliant Package Option APPLICATIONS • • • • • MCNS/DOCSIS Compliant Cable Modems CATV Interactive Set-Top Box OpenCable Set-Top Box Fiber Nodes Cable Modem Termination Systems (CMTS) S12 Package 28 Pin SSOP with Heat Slug PRODUCT DESCRIPTION The ARA05050 is a GaAs IC designed to provide the reverse path amplification and output level control functions in a CATV Set-Top Box or Cable Modem. It incorporates a digitally controlled precision step attenuator that is preceded by an ultra low noise amplifier stage, and followed by an ultra-linear output driver amplifier. This device is capable of meeting the MCNS/DOCSIS requirements for harmonic 4 Attenuation Control performance at a +58dBmV output level while requiring only a single polarity +5V supply. Both the input and the output are single-ended and matched to 75 Ohms. The precision attenuator provides up to 30 dB of attenuation in 2 dB increments. The ARA05050 is offered in a 28-pin SSOP package that features a heat slug on the bottom of the package, and is available in a RoHS-compliant option. Switch ARA05050 LPF Balun Upstream QPSK/16QAM Modulator Clock Data RAM ROM 5-42 MHz Transmit Enable/Disable MAC Clock Data Microcontroller with Ethernet MAC Diplexer 54-860 MHz DoubleConversion Tuner 44 MHz SAW Filter QAM Receiver with FEC 10Base-T Transceiver RJ45 Connector Figure 1. Cable Modem or Set Top Box Application Diagram 05/2005 ARA05050 RFOUT1 ATTIN ATTOUT RFIN2 30 dB, 2dB step digital attenuator section RFIN A1 A2 RFOUT ISET1 16 dB 8 dB 4 dB 2 dB ISET2 Figure 2: Functional Block Diagram 1 2 3 4 5 6 7 8 9 10 11 12 13 14 N/C Bypass ATTIN RFOUT1 VREF1 ATTACG1 ATTACG1 ATTACG1 ATTACG1 RFIN ISET1 VATT 16 dB 8 dB N/C N/C ATTOUT ISET2 RFIN2 ATTACG2 ATTACG2 ATTACG2 ATTACG2 VREF2 RFOUT GND 2 dB 4 dB 28 27 26 25 24 23 22 21 20 19 18 17 16 15 Figure 3: Pinout 2 Data Sheet - Rev 2.2 05/2005 ARA05050 Table 1: Pin Description PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 NAME N/C Bypass ATTIN RFOUT1 VREF1 ATTACG1 ATTACG1 ATTACG1 ATTACG1 RFIN ISET1 VATT 16 dB 8 dB DESCRIPTION No Connection Internal bypass Attenuator Input (2) Amplifier A1 Output and Supply Reference Voltage for Amplifier A1 Attenuator AC Ground 1 Attenuator AC Ground 1 Attenuator AC Ground 1 Attenuator AC Ground 1 Amplifier A1 Input (4) Amplifier A1 Current Adjust (4) Attenuator Supply 16 dB Attenution Control Bit 82 dB Attenution Control Bit (3) (1) PIN 15 16 17 18 19 20 21 22 23 24 25 26 27 28 NAME 4 dB 2 dB GND RFOUT VREF2 ATTACG2 ATTACG2 ATTACG2 ATTACG2 RFIN2 ISET2 ATTOUT N/C N/C DESCRIPTION 4 dB Attenution Control Bit 2 dB Attenution Control Bit Ground Amplifier A2 Output and Supply Reference Voltage for Amplifier A2 Attenuator AC Ground 2 Attenuator AC Ground 2 Attenuator AC Ground 2 Attenuator AC Ground 2 Amplifier A2 Input (4) Amplifier A2 Current Adjust (4) Attenuator Output (2) No Connection No Connection (1) (3) (3) (3) (3) (3) (3) (3) (1) Notes: (1) All N/C pins should be grounded. (2) Pins should be AC-coupled. No external DC bias should be applied. (3) Pins should be AC-grounded. No external DC bias should be applied. (4) Pins should be grounded or pulled to ground through a resistor. No external DC bias should be applied. Data Sheet - Rev 2.2 05/2005 3 ARA05050 ELECTRICAL CHARACTERISTICS Table 2: Absolute Minimum and Maximum Ratings PARAMETER Analog Supply: VSUP (pins 4, 12, 18) Amplifier Reference Voltages (pins 5, 19) RF Power at Ampli fi er Inputs (pins 10, 24) MIN 0 -2.5 0 -55 - MAX 9 VSUP 2 +60 6 +200 260 5 UNIT VDC VD C dBmV V o Attenuator Controls (pins 13, 14, 15, 16) Storage Temperature Soldering Temperature Soldering Time C C o S ec Stresses in excess of the absolute ratings may cause permanent damage. Functional operation is not implied under these conditions. Exposure to absolute ratings for extended periods of time may adversely affect reliability. Notes: 1. Pins 3 and 26 should be AC-coupled. No external DC bias should be applied. 2. Pins 10, 11, 24 and 25 should be grounded or pulled to ground through a resistor. No external DC bias should be applied. 3. Pins 6, 7, 8, 9, 20, 21, 22 and 23 should be AC-grounded. No external DC bias should be applied. Table 3: Operating Ranges PARAMETER Amplifier Supply: VDD (pins 4, 18) Attenuator Supply: VATTN (pin 12) Attenuator Controls (pins 13, 14, 15, 16) Amplifier Reference Voltages (pins 5, 19) Case Temperature MIN 4.5 VDD-0.5 0 -40 TYP 5 5 1.75 25 MAX 7 7 5.5 85 UNIT VDC VD C V VD C o C The device may be operated safely over these conditions; however, parametric performance is guaranteed only over the conditions defined in the electrical specifications. 4 Data Sheet - Rev 2.2 05/2005 ARA05050 Table 4: DC Electrical Specifications TA=25°C; VDD, VATTN = +5.0 VDC PARAMETER Amplifier A1 Current (pin 4) Amplifier A2 Current (pin 18) Attenuator Current (pin 12) Total Power Consumption MIN - TYP 75 100 8 0.92 MAX 95 130 1.2 UNIT mA mA mA W Table 5: AC Electrical Specifications TA=25°C; VDD, VATTN = +5.0 VDC PARAMETER Gain (10 MHz) ARA05050 ARA05050R Gain Flatness Gain Variation over Temperature Attenuation Steps 2 dB 4 dB 8 dB 16 dB 2nd Harmonic Distortion Level 5 MHz 25 MHz 3rd Harmonic Distortion Level 5 MHz 25 MHz 3rd Order Output Intercept 1 dB Gain Compression Point Noise Figure 1.6 3.8 8.0 16.0 78 1.85 4.0 8.3 16.6 -60 -63 -63 -63 70 1.7 2.2 4.2 8.5 17.0 -55 -55 -60 -60 2.5 dB 5 to 42 MHz (1), Monotonic MIN TYP MAX UNIT COMMENTS 30 31 - 32 32 0.75 -0.006 33 33 1.5 - dB dB dB/°C 0 dB attenuation setting 5 to 100 MHz dB c +58 dBmV into 75 Ohms dB c dBmV dBmV dB +58 dBmV into 75 Ohms Notes: (1) See Figures 5 and 6 for performance at higher frequencies. All specifications as measured in ANADIGICS test fixture. Data Sheet - Rev 2.2 05/2005 5 ARA05050 continued: AC Electrical Specifications TA=25°C; VDD, VATTN = +5.0 VDC PARAMETER Output Noise Power Active / No Signal / Min. Atten. Set. Active / No Signal / Max. Atten. Set. Input Impedance Input Return Loss Output Impedance Output Return Loss Note: As measured in ANADIGICS test fixture MIN - TYP 75 -20 75 -20 MAX -37.6 -54.6 -15 -15 UNIT dBmV Ohms dB Ohms dB COMMENTS Any 160 kHz bandwidth from 5 to 42 MHz 75 Ohm system 75 Ohm system Table 6: Logic Interface Specifications TA=25°C; VDD, VATTN = +5.0 VDC PARAMETER Attenuator Control Logic VIN,LOW VIN,HIGH (1) MIN 0 2.8 - TYP 5K MAX 0.5 5.5 - UNIT COMMENTS Bypasses atten. stage Enables atten. stage V Ohms Attenuator Control Impedance Note: (1) Specification applies when 470 Ohm resistor is connected from pin 2 to ground (see test circuit in Figure 4). Table 7: Attenuator Logic ATTENUATION (dB) 2 dB Logic Input (pin 16) 4 dB Logic Input (pin 15) 8 dB Logic Input (pin 14) 16 dB Logic Input (pin 13) 0 L L L L 2 H L L L 4 L H L L 6 H H L L 8 L L H L 10 H L H L 12 L H H L 14 H H H L 16 L L L H 18 H L L H 20 L H L H 22 H H L H 24 L L H H 26 H L H H 28 L H H H 30 H H H H Note: “L” = logic low, “H” = logic high 6 Data Sheet - Rev 2.2 05/2005 +5 V 1uF Note: The 470 Ohm resistor from pin 2 to ground is installed for 3V attenuator control logic levels. For 5V logic, the 470 Ohm resistor is removed. 470 Ohms (see note) 1 28 27 26 25 24 23 0.01uF N/C N/C N/C 5K Ohms 0.1uF ATTOUT ISET2 RFIN2 ATTACG2 ATTACG2 ATTACG2 ATTACG2 VREF2 RFOUT GND 2 dB 4 dB ARA05050 5K Ohms 8 dB 4 dB 16 dB 2 dB +5 V 1uF 17 16 15 18 19 20 21 22 3.3K Ohms Bypass ATTIN RFOUT1 VREF1 ATTACG1 ATTACG1 ATTACG1 ATTACG1 RFIN ISET1 VATT 16 dB 8 dB 1uF 0.01uF 0.1uF 620 Ohms 1uF 0.1uF 3 4 5 10uH 2 1uF 20 Ohms 0.01uF 7 8 9 10 6 0.1uF 1.8K Ohms 1pF 1uF 620 Ohms Figure 4: Test Circuit 0.1uF 11 12 Data Sheet - Rev 2.2 05/2005 20 Ohms 0.01uF 13 14 RF Input (75 Ohms) 0.1uF 1.8K Ohms RF Output (75 Ohms) 0.1uF 10uH 3.3K Ohms 3.9 Ohms 1uF +5 V 0.01uF ARA05050 7 ARA05050 PERFORMANCE DATA Figure 5: S21 (0 - 16 dB Attenuation) Figure 6: S21 (16 - 30 dB Attenuation) Figure 7: S11 - Log Scale Figure 8: S22 - Log Scale Figure 9: S11 - Smith Chart Figure 10: S22 - Smith Chart 8 Data Sheet - Rev 2.2 05/2005 ARA05050 Figure 11: Attenuator Switching Speed - 16 dB Step Figure 12: Harmonic Performance Data Sheet - Rev 2.2 05/2005 9 ARA05050 APPLICATION INFORMATION Printed Circuit Board Layout Considerations The ARA05050 is a high-performance RF device. Special consideration must be given to certain features of the the printed circuit board layout, as they can affect the RF performance of the IC. Refer to the ANADIGICS application note “CATV Reverse Amp w/ Step Attenuator” for more details. Amplifier Enable / Disable The ARA05050 includes two amplification stages that each can be shut down through external control pins VREF1 and VREF2 (pins 5 and 19, respectively.) By applying a typical bias of 1.75 Volts to these pins, the amplifiers are enabled. In order to fully disable an amplifier, its control pin requires a negative bias of -1.5 to -2.0 Volts. Amplifier Bias Current The ISET pins (11 and 25) set the bias current for the amplification stages. Grounding these pins results in the maximum possible current. By placing a resistor from the pin to ground, the current can be reduced. The recommended bias conditions use the configuration shown in the test circuit schematic in Figure 4. Thermal Layout Considerations The device package for the ARA05050 features a heat slug on the bottom of the package body. Use of the heat slug is an integral part of the device design. Soldering it to the ground plane of the PC board will ensure the lowest possible thermal resistance for the device, and will result in the longest MTF (mean time to failure.) A PC board layout that optimizes the benefits of the heat slug is shown in Figure 13. The via holes located under the body of the device must be plated through to a ground plane layer of metal, in order to provide sufficient thermal conductivity. The recommended solder mask outline is shown in Figure 14. ESD Sensitivity Electrostatic discharges can cause permanent damage to this device. Electrostatic charges accumulate on test equipment and the human body, and can discharge without detection. Proper precautions and handling are strongly recommended. Refer to the ANADIGICS application note on ESD precautions. Figure 13: PC Board Layout 10 Data Sheet - Rev 2.2 05/2005 ARA05050 Figure 14: Solder Mask Outline Data Sheet - Rev 2.2 05/2005 11 ARA05050 PACKAGE OUTLINE Figure 15: S12 Package Outline - 28 Pin SSOP with Heat Slug 12 Data Sheet - Rev 2.2 05/2005 ARA05050 COMPONENT PACKAGING Volume quantities of the ARA05050 are supplied on tape and reel. Each reel holds 3,500 pieces. Smaller quantities are available in plastic tubes of 50 pieces. Figure 16: Reel Dimensions DIRECTION OF FEED Figure 17: Tape Dimensions Data Sheet - Rev 2.2 05/2005 13 ARA05050 NOTES 14 Data Sheet - Rev 2.2 05/2005 ARA05050 NOTES Data Sheet - Rev 2.2 05/2005 15 ARA05050 ORDERING INFORMATION ORDER NUMBER ARA05050S12CTR ARA05050S12C TEMPERATURE RANGE -40 to 85 0C -40 to 85 0C PACKAGE DESCRIPTION 28 Pin SSOP with Heat Slug 28 Pin SSOP with Heat Slug RoHS-compliant 28 Pin SSOP with Heat Slug COMPONENT PACKAGING 3,500 piece tape and reel Plastic tubes (50 pieces per tube) ARA05050RS12P1 -40 to 85 0C 3,500 piece tape and reel ANADIGICS, Inc. 141 Mount Bethel Road Warren, New Jersey 07059, U.S.A. Tel: +1 (908) 668-5000 Fax: +1 (908) 668-5132 URL: http://www.anadigics.com E-mail: Mktg@anadigics.com IMPORTANT NOTICE ANADIGICS, Inc. reserves the right to make changes to its products or to discontinue any product at any time without notice. The product specifications contained in Advanced Product Information sheets and Preliminary Data Sheets are subject to change prior to a product’s formal introduction. Information in Data Sheets have been carefully checked and are assumed to be reliable; however, ANADIGICS assumes no responsibilities for inaccuracies. ANADIGICS strongly urges customers to verify that the information they are using is current before placing orders. WARNING ANADIGICS products are not intended for use in life support appliances, devices or systems. Use of an ANADIGICS product in any such application without written consent is prohibited. 16 Data Sheet - Rev 2.2 05/2005